SILCloner: correctly map function argument types in cloneFunction

and remove the now unused `SILBasicBlock::cloneArgumentList`

Author: eeckstein

include/swift/SIL/SILBasicBlock.h

@@ -368,8 +368,6 @@ public SwiftObjectHeader {
   const SILArgument *getArgument(unsigned i) const { return ArgumentList[i]; }
   SILArgument *getArgument(unsigned i) { return ArgumentList[i]; }
 
-  void cloneArgumentList(SILBasicBlock *Other);
-
   void moveArgumentList(SILBasicBlock *from);
 
   /// Erase a specific argument from the arg list.

include/swift/SIL/SILCloner.h

@@ -840,7 +840,12 @@ void SILCloner<ImplClass>::cloneFunction(SILFunction *origF) {
   SILFunction *newF = &Builder.getFunction();
 
   auto *newEntryBB = newF->createBasicBlock();
-  newEntryBB->cloneArgumentList(origF->getEntryBlock());
+
+  for (auto *funcArg : origF->begin()->getSILFunctionArguments()) {
+    auto *newArg = newEntryBB->insertFunctionArgument(newEntryBB->getNumArguments(),
+      asImpl().remapType(funcArg->getType()), funcArg->getOwnershipKind(), funcArg->getDecl());
+    newArg->copyFlags(funcArg);
+  }
 
   // Copy the new entry block arguments into a separate vector purely to
   // resolve the type mismatch between SILArgument* and SILValue.

lib/SIL/IR/SILBasicBlock.cpp

@@ -151,25 +151,6 @@ void SILBasicBlock::removeDeadBlock() {
   eraseFromParent();
 }
 
-void SILBasicBlock::cloneArgumentList(SILBasicBlock *Other) {
-  assert(Other->isEntry() == isEntry() &&
-         "Expected to both blocks to be entries or not");
-  if (isEntry()) {
-    assert(args_empty() && "Expected to have no arguments");
-    for (auto *FuncArg : Other->getSILFunctionArguments()) {
-      auto *NewArg =
-          createFunctionArgument(FuncArg->getType(), FuncArg->getDecl());
-      NewArg->copyFlags(FuncArg);
-    }
-    return;
-  }
-
-  for (auto *PHIArg : Other->getSILPhiArguments()) {
-    createPhiArgument(PHIArg->getType(), PHIArg->getOwnershipKind(),
-                      PHIArg->getDecl());
-  }
-}
-
 void SILBasicBlock::moveArgumentList(SILBasicBlock *from) {
   ArgumentList = std::move(from->ArgumentList);
   for (SILArgument *arg : getArguments()) {