Replace "no-frame-pointer-*" function attributes with "frame-pointer"

Part of the effort to refactoring frame pointer code generation. We used
to use two function attributes "no-frame-pointer-elim" and
"no-frame-pointer-elim-non-leaf" to represent three kinds of frame
pointer usage: (all) frames use frame pointer, (non-leaf) frames use
frame pointer, (none) frame use frame pointer. This CL makes the idea
explicit by using only one enum function attribute "frame-pointer"

Option "-frame-pointer=" replaces "-disable-fp-elim" for tools such as
llc.

"no-frame-pointer-elim" and "no-frame-pointer-elim-non-leaf" are still
supported for easy migration to "frame-pointer".

tests are mostly updated with

// replace command line args ‘-disable-fp-elim=false’ with ‘-frame-pointer=none’
grep -iIrnl '\-disable-fp-elim=false' * | xargs sed -i '' -e "s/-disable-fp-elim=false/-frame-pointer=none/g"

// replace command line args ‘-disable-fp-elim’ with ‘-frame-pointer=all’
grep -iIrnl '\-disable-fp-elim' * | xargs sed -i '' -e "s/-disable-fp-elim/-frame-pointer=all/g"

Patch by Yuanfang Chen (tabloid.adroit)!

Differential Revision: https://reviews.llvm.org/D56351

llvm-svn: 351049
diff --git a/llvm/lib/Target/ARM/ARMFrameLowering.cpp b/llvm/lib/Target/ARM/ARMFrameLowering.cpp
index 2417166..a9d87ce 100644
--- a/llvm/lib/Target/ARM/ARMFrameLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMFrameLowering.cpp
@@ -79,12 +79,11 @@
     : TargetFrameLowering(StackGrowsDown, sti.getStackAlignment(), 0, 4),
       STI(sti) {}
 
-bool ARMFrameLowering::noFramePointerElim(const MachineFunction &MF) const {
+bool ARMFrameLowering::keepFramePointer(const MachineFunction &MF) const {
   // iOS always has a FP for backtracking, force other targets to keep their FP
   // when doing FastISel. The emitted code is currently superior, and in cases
   // like test-suite's lencod FastISel isn't quite correct when FP is eliminated.
-  return TargetFrameLowering::noFramePointerElim(MF) ||
-         MF.getSubtarget<ARMSubtarget>().useFastISel();
+  return MF.getSubtarget<ARMSubtarget>().useFastISel();
 }
 
 /// Returns true if the target can safely skip saving callee-saved registers