LLVM would miscompile ASM dialects when compiling for PPC. Added dialects for
the X86 and PPC backends. It defaults to "0", the first variant of a compound
inline asm expression.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33246 91177308-0d34-0410-b5e6-96231b3b80d8