Move estimateStackSize from ARM into MachineFrameInfo

This is a generic function (derived from PEI); moving it into
MachineFrameInfo eliminates a current redundancy between the ARM and AArch64
backends, and will allow it to be used by the PowerPC target code.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177111 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachineFrameInfo.h

@@ -419,6 +419,9 @@ public:
   ///
   void setStackSize(uint64_t Size) { StackSize = Size; }
 
+  /// Estimate and return the size of the stack frame.
+  unsigned estimateStackSize(const MachineFunction &MF) const;
+
   /// getOffsetAdjustment - Return the correction for frame offsets.
   ///
   int getOffsetAdjustment() const { return OffsetAdjustment; }