[IDE] Use getStartLoc() for matching pattern ranges

For Example `getLoc()` for `foo as Ty`(`IsPattern`) is at 'as'. We
should try to resolve this at position of 'foo'.

Author: rintaro

lib/IDE/SwiftSourceDocInfo.cpp

@@ -581,7 +581,7 @@ std::pair<bool, Pattern*> NameMatcher::walkToPatternPre(Pattern *P) {
   if (isDone() || shouldSkip(P->getSourceRange()))
     return std::make_pair(false, P);
 
-  tryResolve(ASTWalker::ParentTy(P), P->getLoc());
+  tryResolve(ASTWalker::ParentTy(P), P->getStartLoc());
   return std::make_pair(!isDone(), P);
 }
 

test/refactoring/rename/Outputs/local/catch_1.swift.expected

@@ -32,7 +32,7 @@ struct Err1 : Error { }
 func test4(arg: () throws -> Void) {
   do {
     try arg()
-  } catch let x as Err1 {
+  } catch let xRenamed as Err1 {
     print(xRenamed)
   } catch let x {
     print(x)