Update two options to my proposed syntax for user-facing driver options:

  -gcc-toolchain foo  ->  --gcc-toolchain=foo
  -target foo         ->  --target=foo

I've added legacy aliases for the original spellings. I've updated the
canonical tests to check both spellings, and switched all of the
-gcc-toolchain usages elsewhere in the test suite to use the new one.
I've updated some of the usages of -target to the new syntax, but will
finish that in a separate entirely mechanical change once I'm sure this
won't get rolled back for some reason (It touches a *huge* number of RUN
lines in the test suite unsurprisingly).

A nice result is that the three most common flags I end up using when
doing cross compiles are all now consistent: --target=, --sysroot=, and
--gcc-toolchain=.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184408 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Driver/mips-cs-header-search.cpp b/test/Driver/mips-cs-header-search.cpp
index e59fadc..5538031 100644
--- a/test/Driver/mips-cs-header-search.cpp
+++ b/test/Driver/mips-cs-header-search.cpp
@@ -2,8 +2,8 @@
 //
 // = Big-endian, hard float
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mips-linux-gnu \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mips-linux-gnu \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-BE-HF-32 %s
 // CHECK-BE-HF-32: "-internal-isystem"
 // CHECK-BE-HF-32: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -18,8 +18,8 @@
 //
 // = Big-endian, hard float, mips16
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mips-linux-gnu -mips16 \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mips-linux-gnu -mips16 \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-BE-HF-16 %s
 // CHECK-BE-HF-16: "-internal-isystem"
 // CHECK-BE-HF-16: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -34,8 +34,8 @@
 //
 // = Big-endian, hard float, micromips
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mips-linux-gnu -mmicromips \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mips-linux-gnu -mmicromips \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-BE-HF-MICRO %s
 // CHECK-BE-HF-MICRO: "-internal-isystem"
 // CHECK-BE-HF-MICRO: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -50,8 +50,8 @@
 //
 // = Big-endian, soft float
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mips-linux-gnu -msoft-float \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mips-linux-gnu -msoft-float \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-BE-SF-32 %s
 // CHECK-BE-SF-32: "-internal-isystem"
 // CHECK-BE-SF-32: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -66,8 +66,8 @@
 //
 // = Big-endian, soft float, mips16
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mips-linux-gnu -msoft-float -mips16 \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mips-linux-gnu -msoft-float -mips16 \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-BE-SF-16 %s
 // CHECK-BE-SF-16: "-internal-isystem"
 // CHECK-BE-SF-16: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -82,8 +82,8 @@
 //
 // = Big-endian, soft float, micromips
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mips-linux-gnu -msoft-float -mmicromips \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mips-linux-gnu -msoft-float -mmicromips \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-BE-SF-MICRO %s
 // CHECK-BE-SF-MICRO: "-internal-isystem"
 // CHECK-BE-SF-MICRO: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -98,8 +98,8 @@
 //
 // = Big-endian, hard float, 64-bit
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mips64-linux-gnu \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mips64-linux-gnu \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-BE-HF-64 %s
 // CHECK-BE-HF-64: "-internal-isystem"
 // CHECK-BE-HF-64: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -114,8 +114,8 @@
 //
 // = Big-endian, soft float, 64-bit
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mips64-linux-gnu -msoft-float \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mips64-linux-gnu -msoft-float \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-BE-SF-64 %s
 // CHECK-BE-SF-64: "-internal-isystem"
 // CHECK-BE-SF-64: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -130,8 +130,8 @@
 //
 // = Little-endian, hard float
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mipsel-linux-gnu -mhard-float \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mipsel-linux-gnu -mhard-float \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-EL-HF-32 %s
 // CHECK-EL-HF-32: "-internal-isystem"
 // CHECK-EL-HF-32: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -146,8 +146,8 @@
 //
 // = Little-endian, hard float, mips16
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mipsel-linux-gnu -mips16 \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mipsel-linux-gnu -mips16 \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-EL-HF-16 %s
 // CHECK-EL-HF-16: "-internal-isystem"
 // CHECK-EL-HF-16: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -162,8 +162,8 @@
 //
 // = Little-endian, hard float, micromips
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mipsel-linux-gnu -mmicromips \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mipsel-linux-gnu -mmicromips \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-EL-HF-MICRO %s
 // CHECK-EL-HF-MICRO: "-internal-isystem"
 // CHECK-EL-HF-MICRO: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -178,8 +178,8 @@
 //
 // = Little-endian, soft float
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mipsel-linux-gnu -mfloat-abi=soft \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mipsel-linux-gnu -mfloat-abi=soft \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-EL-SF-32 %s
 // CHECK-EL-SF-32: "-internal-isystem"
 // CHECK-EL-SF-32: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -194,8 +194,8 @@
 //
 // = Little-endian, soft float, mips16
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mipsel-linux-gnu -mips16 -msoft-float \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mipsel-linux-gnu -mips16 -msoft-float \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-EL-SF-16 %s
 // CHECK-EL-SF-16: "-internal-isystem"
 // CHECK-EL-SF-16: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -210,8 +210,8 @@
 //
 // = Little-endian, soft float, micromips
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mipsel-linux-gnu -mmicromips -msoft-float \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mipsel-linux-gnu -mmicromips -msoft-float \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-EL-SF-MICRO %s
 // CHECK-EL-SF-MICRO: "-internal-isystem"
 // CHECK-EL-SF-MICRO: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -226,8 +226,8 @@
 //
 // = Little-endian, hard float, 64-bit
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mips64el-linux-gnu \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mips64el-linux-gnu \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-EL-HF-64 %s
 // CHECK-EL-HF-64: "-internal-isystem"
 // CHECK-EL-HF-64: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"
@@ -242,8 +242,8 @@
 //
 // = Little-endian, soft float, 64-bit
 // RUN: %clang -no-canonical-prefixes %s -### -c -o %t.o 2>&1 \
-// RUN:     -target mips64el-linux-gnu -msoft-float \
-// RUN:     -gcc-toolchain %S/Inputs/mips_cs_tree \
+// RUN:     --target=mips64el-linux-gnu -msoft-float \
+// RUN:     --gcc-toolchain=%S/Inputs/mips_cs_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-EL-SF-64 %s
 // CHECK-EL-SF-64: "-internal-isystem"
 // CHECK-EL-SF-64: "[[TC:[^"]+/lib/gcc/mips-linux-gnu/4.6.3]]/../../../../mips-linux-gnu/include/c++/4.6.3"