Remove the -cxx-abi command-line flag.

This makes the C++ ABI depend entirely on the target: MS ABI for -win32 triples,
Itanium otherwise. It's no longer possible to do weird combinations.

To be able to run a test with a specific ABI without constraining it to a
specific triple, new substitutions are added to lit: %itanium_abi_triple and
%ms_abi_triple can be used to get the current target triple adjusted to the
desired ABI. For example, if the test suite is running with the i686-pc-win32
target, %itanium_abi_triple will expand to i686-pc-mingw32.

Differential Revision: http://llvm-reviews.chandlerc.com/D2545

llvm-svn: 199250
diff --git a/clang/test/PCH/cxx-required-decls.cpp b/clang/test/PCH/cxx-required-decls.cpp
index f98ce43..c2f8e2f 100644
--- a/clang/test/PCH/cxx-required-decls.cpp
+++ b/clang/test/PCH/cxx-required-decls.cpp
@@ -1,9 +1,9 @@
 // Test this without pch.
-// RUN: %clang_cc1 -include %S/cxx-required-decls.h %s -cxx-abi itanium -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -include %S/cxx-required-decls.h %s -triple %itanium_abi_triple -emit-llvm -o - | FileCheck %s
 
 // Test with pch.
-// RUN: %clang_cc1 -x c++-header -cxx-abi itanium -emit-pch -o %t %S/cxx-required-decls.h
-// RUN: %clang_cc1 -include-pch %t %s -cxx-abi itanium -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -x c++-header -triple %itanium_abi_triple -emit-pch -o %t %S/cxx-required-decls.h
+// RUN: %clang_cc1 -include-pch %t %s -triple %itanium_abi_triple -emit-llvm -o - | FileCheck %s
 
 // CHECK: @_ZL5globS = internal global %struct.S zeroinitializer
 // CHECK: @_ZL3bar = internal global i32 0, align 4