Fix PR15355

- Clear 'mayStore' flag when loading from the atomic variable before the
  spin loop
- Clear kill flag from one use to multiple use in registers forming the
  address to that atomic variable
- don't use a physical register as live-in register in BB (neither entry
  nor landing pad.) by copying it into virtual register

(patch by Cameron Zwarich)

llvm-svn: 176538
diff --git a/llvm/test/CodeGen/X86/atomic-pointer.ll b/llvm/test/CodeGen/X86/atomic-pointer.ll
index a455277..ec3e6c3 100644
--- a/llvm/test/CodeGen/X86/atomic-pointer.ll
+++ b/llvm/test/CodeGen/X86/atomic-pointer.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=i686-none-linux | FileCheck %s
+; RUN: llc < %s -mtriple=i686-none-linux -verify-machineinstrs | FileCheck %s
 
 define i32* @test_atomic_ptr_load(i32** %a0) {
 ; CHECK: test_atomic_ptr_load