Adding -verify-machineinstrs option to PowerPC tests

Currently we have a number of tests that fail with -verify-machineinstrs.
To detect this cases earlier we add the option to the testcases with the
exception of tests that will currently fail with this option. PR 27456 keeps
track of this failures.

No code review, as discussed with Hal Finkel.

llvm-svn: 277624
diff --git a/llvm/test/CodeGen/PowerPC/compare-duplicate.ll b/llvm/test/CodeGen/PowerPC/compare-duplicate.ll
index f5108c3..60e2712 100644
--- a/llvm/test/CodeGen/PowerPC/compare-duplicate.ll
+++ b/llvm/test/CodeGen/PowerPC/compare-duplicate.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=powerpc-apple-darwin8  | not grep slwi
+; RUN: llc -verify-machineinstrs < %s -mtriple=powerpc-apple-darwin8  | not grep slwi
 
 define i32 @test(i32 %A, i32 %B) {
 	%C = sub i32 %B, %A