[CodeGenPrepare] Add missing static decl on matchIncrement(); NFC

Author: goldsteinn

llvm/lib/CodeGen/CodeGenPrepare.cpp

@@ -1499,8 +1499,8 @@ static bool OptimizeNoopCopyExpression(CastInst *CI, const TargetLowering &TLI,
 // Match a simple increment by constant operation.  Note that if a sub is
 // matched, the step is negated (as if the step had been canonicalized to
 // an add, even though we leave the instruction alone.)
-bool matchIncrement(const Instruction *IVInc, Instruction *&LHS,
-                    Constant *&Step) {
+static bool matchIncrement(const Instruction *IVInc, Instruction *&LHS,
+                           Constant *&Step) {
   if (match(IVInc, m_Add(m_Instruction(LHS), m_Constant(Step))) ||
       match(IVInc, m_ExtractValue<0>(m_Intrinsic<Intrinsic::uadd_with_overflow>(
                        m_Instruction(LHS), m_Constant(Step)))))