[Statepoints][NFC] Rename variables to llvm style.

[sanjoy]

Summary

(I don't think this change needs review, this was uploaded to
phabricator to provide context for later dependent changes.)

llvm/trunk/include/llvm/IR/Statepoint.h

enum class StatepointFlags {
 
   MaskAll = GCTransition ///< A bitmask that includes all valid flags.
 };
 
 class GCRelocateOperands;
 class ImmutableStatepoint;
 
 bool isStatepoint(const ImmutableCallSite &CS);
-bool isStatepoint(const Value *inst);
-bool isStatepoint(const Value &inst);
+bool isStatepoint(const Value *V);
+bool isStatepoint(const Value &V);
 
-bool isGCRelocate(const Value *inst);
+bool isGCRelocate(const Value *V);
 bool isGCRelocate(const ImmutableCallSite &CS);
 
-bool isGCResult(const Value *inst);
+bool isGCResult(const Value *V);
 bool isGCResult(const ImmutableCallSite &CS);
 
 /// Analogous to CallSiteBase, this provides most of the actual
 /// functionality for Statepoint and ImmutableStatepoint.  It is
 /// templatized to allow easily specializing of const and non-const
 /// concrete subtypes.  This is structured analogous to CallSite
 /// rather than the IntrinsicInst.h helpers since we want to support
 /// invokable statepoints in the near future.