Revert r164308 to fix buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164309 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index 304e39e..328722b 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -60,8 +60,8 @@
   MFInfo = 0;
   FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameLowering());
   if (Fn->hasFnAttr(Attribute::StackAlignment))
-    FrameInfo->ensureMaxAlignment(Fn->getAttributes().
-                                  getFnAttributes().getStackAlignment());
+    FrameInfo->ensureMaxAlignment(Attribute::getStackAlignmentFromAttrs(
+        Fn->getAttributes().getFnAttributes()));
   ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData());
   Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
   // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.