[clang][LTO] Passing vec-extabi to the Backend on AIX

[qiongsiwu1]

Summary

This patch passes on the vec-extabi mabi option on AIX.

clang/lib/Driver/ToolChains/CommonArgs.cpp

if (IsOSAIX) {
     // specified, unless it is told explicitly not to assume so.
     Arg *A = Args.getLastArg(options::OPT_g_Group);
     bool EnableDebugInfo = A && !A->getOption().matches(options::OPT_g0) &&
                            !A->getOption().matches(options::OPT_ggdb0);
     if (EnableDebugInfo && Args.hasFlag(options::OPT_gstrict_dwarf,
                                         options::OPT_gno_strict_dwarf, true))
       CmdArgs.push_back(
           Args.MakeArgString(Twine(PluginOptPrefix) + "-strict-dwarf=true"));
+
+    if (Args.getLastArg(options::OPT_mabi_EQ_vec_extabi))
+      CmdArgs.push_back(
+          Args.MakeArgString(Twine(PluginOptPrefix) + "-vec-extabi"));
   }
 
   bool UseSeparateSections =
       isUseSeparateSections(ToolChain.getEffectiveTriple());
 
   if (Args.hasFlag(options::OPT_ffunction_sections,
                    options::OPT_fno_function_sections, UseSeparateSections))
     CmdArgs.push_back(

clang/test/Driver/lto-aix.c

 // RUN:   -fuse-ld=ld -flto -O3 -### 2>&1 | FileCheck --check-prefix=O3 %s
 // RUN: %clang --target=powerpc-ibm-aix --sysroot %S/Inputs/aix_ppc_tree %s \
 // RUN:   -fuse-ld=ld -flto -Ofast -### 2>&1 | FileCheck --check-prefix=O3 %s
 //
 // O1: "-bplugin_opt:-O1"
 // O2: "-bplugin_opt:-O2"
 // O3: "-bplugin_opt:-O3"
 //
+// vec-extabi option
+// RUN: %clang --target=powerpc-ibm-aix --sysroot %S/Inputs/aix_ppc_tree %s \
+// RUN:   -fuse-ld=ld -flto -mabi=vec-extabi -### 2>&1 \
+// RUN:   | FileCheck --check-prefix=VECEXTABI %s
+// RUN: %clang --target=powerpc-ibm-aix --sysroot %S/Inputs/aix_ppc_tree %s \
+// RUN:   -fuse-ld=ld -flto -### 2>&1 | FileCheck --check-prefix=NOVECEXTABI %s
+//
+// VECEXTABI: "-bplugin_opt:-vec-extabi"
+// NOVECEXTABI-NOT: "-bplugin_opt:-vec-extabi"
+//
 // Test debugging options
 // RUN: %clang --target=powerpc-ibm-aix -### %s -flto -fuse-ld=ld -gdbx 2>&1 \
 // RUN:   | FileCheck -check-prefix=DBX %s
 // RUN: %clang --target=powerpc-ibm-aix -### %s -flto -fuse-ld=ld -g 2>&1 \
 // RUN:   | FileCheck -check-prefix=NODEBUGGER-TUNE %s
 // RUN: %clang --target=powerpc-ibm-aix-xcoff -### %s -flto -g 2>&1 \
 // RUN:   | FileCheck -check-prefixes=STRICT,NODEBUGGER-TUNE %s
 // RUN: %clang --target=powerpc64-ibm-aix-xcoff -### %s -flto -g 2>&1 \