[clang-rename] cleanup `auto` usages

As Alexander pointed out, LLVM Coding Standards are more conservative about
using auto, i.e. it should be used in the following situations:

* When the type is obvious, i.e. explicitly mentioned in the same expression.
For example `if (const clang::FieldDecl *FieldDecl = Initializer->getMember())`.
* When the type is totally non-obvious and one iterates over something. For
example
`for (const auto &CurrDecl : Context.getTranslationUnitDecl()->decls())`.

Otherwise the type should be explicitly stated.

Reviewers: alexfh

Differential Revision: https://reviews.llvm.org/D23397

llvm-svn: 278760
diff --git a/clang-tools-extra/clang-rename/USRLocFinder.cpp b/clang-tools-extra/clang-rename/USRLocFinder.cpp
index 8d4c7e4..c7ce533 100644
--- a/clang-tools-extra/clang-rename/USRLocFinder.cpp
+++ b/clang-tools-extra/clang-rename/USRLocFinder.cpp
@@ -67,7 +67,7 @@
   // Expression visitors:
 
   bool VisitDeclRefExpr(const DeclRefExpr *Expr) {
-    const auto *Decl = Expr->getFoundDecl();
+    const NamedDecl *Decl = Expr->getFoundDecl();
 
     if (USRSet.find(getUSRForDecl(Decl)) != USRSet.end()) {
       const SourceManager &Manager = Decl->getASTContext().getSourceManager();
@@ -79,7 +79,7 @@
   }
 
   bool VisitMemberExpr(const MemberExpr *Expr) {
-    const auto *Decl = Expr->getFoundDecl().getDecl();
+    const NamedDecl *Decl = Expr->getFoundDecl().getDecl();
     if (USRSet.find(getUSRForDecl(Decl)) != USRSet.end()) {
       const SourceManager &Manager = Decl->getASTContext().getSourceManager();
       SourceLocation Location = Manager.getSpellingLoc(Expr->getMemberLoc());
@@ -116,7 +116,8 @@
   // Namespace traversal:
   void handleNestedNameSpecifierLoc(NestedNameSpecifierLoc NameLoc) {
     while (NameLoc) {
-      const auto *Decl = NameLoc.getNestedNameSpecifier()->getAsNamespace();
+      const NamespaceDecl *Decl =
+          NameLoc.getNestedNameSpecifier()->getAsNamespace();
       if (Decl && USRSet.find(getUSRForDecl(Decl)) != USRSet.end()) {
         checkAndAddLocation(NameLoc.getLocalBeginLoc());
       }
@@ -126,8 +127,8 @@
 
 private:
   void checkAndAddLocation(SourceLocation Loc) {
-    const auto BeginLoc = Loc;
-    const auto EndLoc = Lexer::getLocForEndOfToken(
+    const SourceLocation BeginLoc = Loc;
+    const SourceLocation EndLoc = Lexer::getLocForEndOfToken(
         BeginLoc, 0, Context.getSourceManager(), Context.getLangOpts());
     StringRef TokenName =
         Lexer::getSourceText(CharSourceRange::getTokenRange(BeginLoc, EndLoc),