Fix build failures due to Tyoe::dump() api difference + string conversions

Author: Nathan Hawes

Diff for: include/swift/AST/ExtInfo.h

@@ -30,6 +30,7 @@
 
 namespace clang {
 class Type;
+class ASTContext;
 } // namespace clang
 
 namespace swift {
@@ -77,7 +78,7 @@ class ClangTypeInfo {
   /// Use the ClangModuleLoader to print the Clang type as a string.
   void printType(ClangModuleLoader *cml, llvm::raw_ostream &os) const;
 
-  void dump(llvm::raw_ostream &os) const;
+  void dump(llvm::raw_ostream &os, const clang::ASTContext &ctx) const;
 };
 
 // MARK: - FunctionTypeRepresentation

Diff for: lib/AST/ExtInfo.cpp

@@ -43,9 +43,10 @@ void ClangTypeInfo::printType(ClangModuleLoader *cml,
   cml->printClangType(type, os);
 }
 
-void ClangTypeInfo::dump(llvm::raw_ostream &os) const {
+void ClangTypeInfo::dump(llvm::raw_ostream &os,
+                         const clang::ASTContext &ctx) const {
   if (type) {
-    type->dump(os);
+    type->dump(os, ctx);
   } else {
     os << "<nullptr>";
   }

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

@@ -235,7 +235,7 @@ bool StringOptimization::optimizeStringConcat(ApplyInst *concatCall) {
 
   // Replace lhs + rhs with "lhs + rhs" if both lhs and rhs are constant.
   if (lhsString.isConstant() && rhsString.isConstant()) {
-    std::string concat = lhsString.str;
+    std::string concat = lhsString.str.str();
     concat += rhsString.str;
     if (ApplyInst *stringInit = createStringInit(concat, concatCall)) {
       concatCall->replaceAllUsesWith(stringInit);