Add a new string member to the TargetOptions struct for the name

of the abi we should be using. For targets that don't use the
option there's no change, otherwise this allows external users
to set the ABI via string and avoid some of the -backend-option
pain in clang.

Use this option to move the ABI for the ARM port from the
Subtarget to the TargetMachine and update the testcases
accordingly since it's no longer valid to set via -mattr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224492 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/TargetOptionsImpl.cpp

@@ -58,3 +58,10 @@ StringRef TargetOptions::getTrapFunctionName() const {
 StringRef TargetOptions::getCFIFuncName() const {
   return CFIFuncName;
 }
+
+/// getABIName - If this returns a non-empty string this represents the
+/// textual name of the ABI that we want the backend to use, e.g. o32, or
+/// aapcs-linux.
+StringRef TargetOptions::getABIName() const {
+  return ABIName;
+}