Revert r211866, r211895 and r211995, "Driver: use GNU::Link for the Generic_GCC toolchain". It broke users of Generic_GCC, cygwin and mingw32.

It reverts commits as follows:
  r211866: "Driver: use GNU::Link for the Generic_GCC toolchain"
  r211895: "Replace GetProgramPath("ld") with GetLinkerPath()."
  r211995: "Driver: add a cygwin linker tool"

llvm-svn: 211998
diff --git a/clang/test/Driver/gcc_forward.c b/clang/test/Driver/gcc_forward.c
index a58cd9f..3bc4131 100644
--- a/clang/test/Driver/gcc_forward.c
+++ b/clang/test/Driver/gcc_forward.c
@@ -17,14 +17,14 @@
 // CHECK: as{{[^"]*}}"
 // CHECK: "-o" "{{[^"]+}}.o"
 //
-// gnu-ld
-// CHECK: ld{{[^"]*}}"
+// gcc-ld
+// CHECK: gcc{{[^"]*}}"
 // CHECK-NOT: "-mlinker-version=10"
 // CHECK-NOT: "-Xclang"
 // CHECK-NOT: "foo-bar"
 // CHECK-NOT: "-Wall"
 // CHECK-NOT: "-Wdocumentation"
-// CHECK-NOT: "-march"
+// CHECK: -march
 // CHECK-NOT: "-mlinker-version=10"
 // CHECK-NOT: "-Xclang"
 // CHECK-NOT: "foo-bar"