Provide SimpleLoopUnswitch binding for legacy pass manager

[penzn]

Summary

Provide a straight-forward binding for adding SimpleLoopUnswich pass using legacy pass manager.

[nikic]

The legacy pass manager is deprecated and in the process of being removed. We should not expose any new bindings for it.

[penzn]

Implemented locally instead

llvm/include/llvm-c/Transforms/Scalar.h

 
 /** See llvm::createSROAPass function. */
 void LLVMAddScalarReplAggregatesPassSSA(LLVMPassManagerRef PM);
 
 /** See llvm::createSROAPass function. */
 void LLVMAddScalarReplAggregatesPassWithThreshold(LLVMPassManagerRef PM,
                                                   int Threshold);
 
+/** See llvm::createSimpleLoopUnswitchPass function. */
+void LLVMAddSimpleLoopUnswitchPass(LLVMPassManagerRef PM);
+
 /** See llvm::createSimplifyLibCallsPass function. */
 void LLVMAddSimplifyLibCallsPass(LLVMPassManagerRef PM);
 
 /** See llvm::createTailCallEliminationPass function. */
 void LLVMAddTailCallEliminationPass(LLVMPassManagerRef PM);
 
 /** See llvm::demotePromoteMemoryToRegisterPass function. */
 void LLVMAddDemoteMemoryToRegisterPass(LLVMPassManagerRef PM);

llvm/lib/Transforms/Scalar/Scalar.cpp

 #include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/ScopedNoAliasAA.h"
 #include "llvm/Analysis/TypeBasedAliasAnalysis.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Transforms/Scalar/GVN.h"
 #include "llvm/Transforms/Scalar/Scalarizer.h"
+#include "llvm/Transforms/Scalar/SimpleLoopUnswitch.h"
 #include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
 
 using namespace llvm;
 
 /// initializeScalarOptsPasses - Initialize all passes linked into the
 /// ScalarOpts library.
 void llvm::initializeScalarOpts(PassRegistry &Registry) {
   initializeADCELegacyPassPass(Registry);
void LLVMAddScalarReplAggregatesPassWithThreshold(LLVMPassManagerRef PM,
                                                   int Threshold) {
   unwrap(PM)->add(createSROAPass());
 }
 
 void LLVMAddSimplifyLibCallsPass(LLVMPassManagerRef PM) {
   // NOTE: The simplify-libcalls pass has been removed.
 }
 
+void LLVMAddSimpleLoopUnswitchPass(LLVMPassManagerRef PM) {
+  unwrap(PM)->add(createSimpleLoopUnswitchLegacyPass());
+}
+
 void LLVMAddTailCallEliminationPass(LLVMPassManagerRef PM) {
   unwrap(PM)->add(createTailCallEliminationPass());
 }
 
 void LLVMAddDemoteMemoryToRegisterPass(LLVMPassManagerRef PM) {
   unwrap(PM)->add(createDemoteRegisterToMemoryPass());
 }