Fix nasty mingw32 bug, which e.g. prevented llvm-gcc bootstrap there.
Mark _alloca call as clobberring EFLAGS, otherwise some DCE might remove
other flags-clobberring stuff (e.g. cmp instructions) occuring after
_alloca call.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112034 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 7adaf97..dc1bab3 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -8930,7 +8930,8 @@
     .addReg(X86::EAX, RegState::Implicit)
     .addReg(X86::ESP, RegState::Implicit)
     .addReg(X86::EAX, RegState::Define | RegState::Implicit)
-    .addReg(X86::ESP, RegState::Define | RegState::Implicit);
+    .addReg(X86::ESP, RegState::Define | RegState::Implicit)
+    .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit);
 
   MI->eraseFromParent();   // The pseudo instruction is gone now.
   return BB;