Mark a couple of local sil-optimizer functions as static NFC

Author: benlangmuir

Diff for: lib/SILOptimizer/Transforms/CSE.cpp

@@ -686,7 +686,7 @@ using ApplyWitnessPair = std::pair<ApplyInst *, WitnessMethodInst *>;
 /// Returns the Apply and WitnessMethod instructions that use the
 /// open_existential_addr instructions, or null if at least one of the
 /// instructions is missing.
-ApplyWitnessPair getOpenExistentialUsers(OpenExistentialAddrInst *OE) {
+static ApplyWitnessPair getOpenExistentialUsers(OpenExistentialAddrInst *OE) {
   ApplyInst *AI = nullptr;
   WitnessMethodInst *WMI = nullptr;
   ApplyWitnessPair Empty = std::make_pair(nullptr, nullptr);

Diff for: lib/SILOptimizer/Transforms/SimplifyCFG.cpp

@@ -2751,8 +2751,8 @@ getSILValueFromCaseResult(SILBuilder &B, SILLocation Loc,
 /// a given enum is of a given tag.  If so, create a new select_enum instruction
 /// This is used to simplify arbitrary simple switch_enum diamonds into
 /// select_enums.
-bool simplifySwitchEnumToSelectEnum(SILBasicBlock *BB, unsigned ArgNum,
-                                    SILArgument *IntArg) {
+static bool simplifySwitchEnumToSelectEnum(SILBasicBlock *BB, unsigned ArgNum,
+                                           SILArgument *IntArg) {
 
   // Don't know which values should be passed if there is more
   // than one basic block argument.