remove fullTypeCheck flag as it may lead to missing errors if we make any requests with fullTypeCheck=false and we cache any result

Author: mhegazy

src/compiler/checker.ts

@@ -58,7 +58,6 @@ module ts {
 
         var stringLiteralTypes: Map<StringLiteralType> = {};
 
-        var fullTypeCheck = false;
         var emitExtends = false;
 
         var mergedSymbols: Symbol[] = [];
@@ -4356,7 +4355,7 @@ module ts {
                     }
                 }
             }
-            if (fullTypeCheck && !(links.flags & NodeCheckFlags.TypeChecked)) {
+            if (!(links.flags & NodeCheckFlags.TypeChecked)) {
                 checkSignatureDeclaration(node);
                 if (node.type) {
                     checkIfNonVoidFunctionHasReturnExpressionsOrSingleThrowStatment(node, getTypeFromTypeNode(node.type));
@@ -6254,7 +6253,6 @@ module ts {
         function checkSourceFile(node: SourceFile) {
             var links = getNodeLinks(node);
             if (!(links.flags & NodeCheckFlags.TypeChecked)) {
-                fullTypeCheck = true;
                 emitExtends = false;
                 potentialThisCollisions.length = 0;
                 forEach(node.statements, checkSourceElement);
@@ -6271,7 +6269,6 @@ module ts {
                 }
                 if (emitExtends) links.flags |= NodeCheckFlags.EmitExtends;
                 links.flags |= NodeCheckFlags.TypeChecked;
-                fullTypeCheck = false;
             }
         }