Remove require name collision check for ES6 modules and later

tests/cases/compiler/es6UseOfTopLevelRequire.ts

@@ -0,0 +1,16 @@
+// @target: ES6
+
+// @filename: b.ts
+export default function require(s: string): void {
+}
+
+// @filename: c.ts
+export const exports = 0;
+export default exports;
+
+// @filename: a.ts
+import require from "./b"
+require("arg");
+
+import exports from "./c"
+var x = exports + 2;