SIL Linker: Use SILModule::loadFunction()

This means SILLinkerVisitor no longer depends on the SILLoader;
the latter is now just an implementation detail of SILModule.

lib/SIL/Linker.cpp

@@ -37,15 +37,13 @@ bool SILLinkerVisitor::addFunctionToWorklist(SILFunction *F) {
 
   DEBUG(llvm::dbgs() << "Imported function: "
                      << F->getName() << "\n");
-  if (auto *NewFn = Loader->lookupSILFunction(F)) {
-    if (NewFn->isExternalDeclaration())
+  if (Mod.loadFunction(F)) {
+    if (F->isExternalDeclaration())
       return false;
 
-    assert(NewFn == F && "This shouldn't happen");
-
-    NewFn->setBare(IsBare);
-    NewFn->verify();
-    Worklist.push_back(NewFn);
+    F->setBare(IsBare);
+    F->verify();
+    Worklist.push_back(F);
     ++NumFuncLinked;
 
     return true;

lib/SIL/Linker.h

@@ -16,7 +16,6 @@
 #include "swift/SIL/SILDebugScope.h"
 #include "swift/SIL/SILVisitor.h"
 #include "swift/SIL/SILModule.h"
-#include "swift/Serialization/SerializedSILLoader.h"
 #include <functional>
 
 namespace swift {
@@ -28,9 +27,6 @@ class SILLinkerVisitor : public SILInstructionVisitor<SILLinkerVisitor, bool> {
   /// The SILModule that we are loading from.
   SILModule &Mod;
 
-  /// The SILLoader that this visitor is using to link.
-  SerializedSILLoader *Loader;
-
   /// Break cycles visiting recursive protocol conformances.
   llvm::DenseSet<ProtocolConformance *> VisitedConformances;
 
@@ -45,9 +41,8 @@ class SILLinkerVisitor : public SILInstructionVisitor<SILLinkerVisitor, bool> {
   LinkingMode Mode;
 
 public:
-  SILLinkerVisitor(SILModule &M, SerializedSILLoader *L,
-                   SILModule::LinkingMode LinkingMode)
-      : Mod(M), Loader(L), Worklist(), FunctionDeserializationWorklist(),
+  SILLinkerVisitor(SILModule &M, SILModule::LinkingMode LinkingMode)
+      : Mod(M), Worklist(), FunctionDeserializationWorklist(),
         Mode(LinkingMode) {}
 
   /// Process F, recursively deserializing any thing F may reference.

lib/SIL/SILModule.cpp

@@ -495,7 +495,7 @@ bool SILModule::loadFunction(SILFunction *F) {
 }
 
 bool SILModule::linkFunction(SILFunction *F, SILModule::LinkingMode Mode) {
-  return SILLinkerVisitor(*this, getSILLoader(), Mode).processFunction(F);
+  return SILLinkerVisitor(*this, Mode).processFunction(F);
 }
 
 SILFunction *SILModule::findFunction(StringRef Name, SILLinkage Linkage) {