[X86] Always generate precise CFA adjustments.

This removes the code path that generate "synchronous" (only correct at call site) CFA.
We will probably want to re-introduce it once we are capable of emitting different
.eh_frame and .debug_frame sections.

Differential Revision: http://reviews.llvm.org/D14948

llvm-svn: 254874
diff --git a/llvm/lib/Target/X86/X86MCInstLower.cpp b/llvm/lib/Target/X86/X86MCInstLower.cpp
index 8878c9f..af38680 100644
--- a/llvm/lib/Target/X86/X86MCInstLower.cpp
+++ b/llvm/lib/Target/X86/X86MCInstLower.cpp
@@ -1143,8 +1143,10 @@
     const X86FrameLowering* FrameLowering =
         MF->getSubtarget<X86Subtarget>().getFrameLowering();
     bool hasFP = FrameLowering->hasFP(*MF);
-
-    bool NeedsDwarfCFI = MMI->usePreciseUnwindInfo();
+    
+    // TODO: This is needed only if we require precise CFA.
+    bool NeedsDwarfCFI = 
+         (MMI->hasDebugInfo() || MF->getFunction()->needsUnwindTableEntry());
     int stackGrowth = -RI->getSlotSize();
 
     if (NeedsDwarfCFI && !hasFP) {