Remove the FrameSizeLocals field which appears to be unused (write-only).

Might have gotten replaced by some other field, but don't
quite remember. Spotted while looking for ways to share
the addProlog() code between targets.

BUG=none
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1158713005
diff --git a/src/IceTargetLoweringX8632.cpp b/src/IceTargetLoweringX8632.cpp
index e7f5c5d..7edb2c3 100644
--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -403,7 +403,7 @@
       InstructionSet(static_cast<X86InstructionSet>(
           Func->getContext()->getFlags().getTargetInstructionSet() -
           TargetInstructionSet::X86InstructionSet_Begin)),
-      IsEbpBasedFrame(false), NeedsStackAlignment(false), FrameSizeLocals(0),
+      IsEbpBasedFrame(false), NeedsStackAlignment(false),
       SpillAreaSizeBytes(0) {
   static_assert((X86InstructionSet::End - X86InstructionSet::Begin) ==
                     (TargetInstructionSet::X86InstructionSet_End -
@@ -1023,7 +1023,6 @@
     else
       Var->setStackOffset(SpillAreaSizeBytes - NextStackOffset);
   }
-  this->FrameSizeLocals = NextStackOffset - SpillAreaPaddingBytes;
   this->HasComputedFrame = true;
 
   // Assign stack offsets to variables that have been linked to spilled
diff --git a/src/IceTargetLoweringX8632.h b/src/IceTargetLoweringX8632.h
index 79557ae..4213a59 100644
--- a/src/IceTargetLoweringX8632.h
+++ b/src/IceTargetLoweringX8632.h
@@ -567,7 +567,6 @@
   const X86InstructionSet InstructionSet;
   bool IsEbpBasedFrame;
   bool NeedsStackAlignment;
-  size_t FrameSizeLocals;
   size_t SpillAreaSizeBytes;
   llvm::SmallBitVector TypeToRegisterSet[IceType_NUM];
   llvm::SmallBitVector ScratchRegs;