Use unsigned comparison in segmented stack prologue.
This is a comparison of two addresses, and GCC does the comparison unsigned.

Patch by Brian Anderson.

llvm-svn: 147954
diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index 058b39a..fba4788 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -1405,7 +1405,7 @@
 
   // This jump is taken if SP >= (Stacklet Limit + Stack Space required).
   // It jumps to normal execution of the function body.
-  BuildMI(checkMBB, DL, TII.get(X86::JG_4)).addMBB(&prologueMBB);
+  BuildMI(checkMBB, DL, TII.get(X86::JA_4)).addMBB(&prologueMBB);
 
   // On 32 bit we first push the arguments size and then the frame size. On 64
   // bit, we pass the stack frame size in r10 and the argument size in r11.