Add ppc-specific test for better i64 compare codegen.
; RUN: llvm-as < %s | llc -march=ppc32 | grep cntlzw &&
; RUN: llvm-as < %s | llc -march=ppc32 | not grep xori &&
; RUN: llvm-as < %s | llc -march=ppc32 | not grep 'li ' &&
; RUN: llvm-as < %s | llc -march=ppc32 | not grep 'mr '

define i1 @test(i64 %x) {
  %tmp = icmp ult i64 %x, 4294967296
  ret i1 %tmp
}