Merge pull request #13686 from Microsoft/goToDefinition_callback

For goToDefinition, verify that tryGetSignatureDeclaration returns a signature declaration and not a FunctionType.

tests/cases/fourslash/goToDefinitionFunctionType.ts

@@ -0,0 +1,17 @@
+/// <reference path='fourslash.ts'/>
+
+// Tests that goToDefinition does not go to a function type; it goes to the value.
+
+////const /*constDefinition*/c: () => void;
+/////*constReference*/c();
+////function test(/*cbDefinition*/cb: () => void) {
+////    /*cbReference*/cb();
+////}
+////class C {
+////    /*propDefinition*/prop: () => void;
+////    m() {
+////        this./*propReference*/prop();
+////    }
+////}
+
+verify.goToDefinitionForMarkers("const", "cb", "prop");