refactor emitMemberName to be used more consistently

lib/runtime/dart/_interceptors.js

 var _interceptors;
 (function(exports) {
   'use strict';
   let JSArray = Array;
   let JSMutableArray$ = dart.generic(function(E) {
     class JSMutableArray extends JSArray$(E) {}
     JSMutableArray[dart.implements] = () => [JSMutableIndexable];
     return JSMutableArray;
   });
   let JSMutableArray = JSMutableArray$();
@@ skipping 208 matching lines @@
     toString() {
       if (dart.notNull(dart.equals(this, 0)) && 1 / this < 0) {
         return '-0.0';
       } else {
         return "" + this;
       }
     }
     get hashCode() {
       return this & 0x1FFFFFFF;
     }
-    ['-']() {
+    ['unary-']() {
       return -this;
     }
     ['+'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return this + other;
     }
     ['-'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
@@ skipping 263 matching lines @@
       _js_helper.checkInt(startIndex);
       if (dart.notNull(startIndex) < 0 || dart.notNull(startIndex) > dart.notNull(this.length)) {
         throw new core.RangeError.range(startIndex, 0, this.length);
       }
       return dart.as(_js_helper.stringReplaceFirstUnchecked(this, from, to, startIndex), core.String);
     }
     split(pattern) {
       _js_helper.checkNull(pattern);
       if (typeof pattern == 'string') {
         return dart.as(this.split(pattern), core.List$(core.String));
-      } else if (dart.notNull(dart.is(pattern, _js_helper.JSSyntaxRegExp)) && _js_helper.regExpCaptureCount(pattern) == 0) {
+      } else if (dart.is(pattern, _js_helper.JSSyntaxRegExp) && _js_helper.regExpCaptureCount(pattern) == 0) {
         let re = _js_helper.regExpGetNative(pattern);
         return dart.as(this.split(re), core.List$(core.String));
       } else {
         return this[_defaultSplit](pattern);
       }
     }
     [_defaultSplit](pattern) {
       let result = new core.List$(core.String).from([]);
       let start = 0;
       let length = 1;
@@ skipping 560 matching lines @@
   exports.findInterceptorForType = findInterceptorForType;
   exports.JSBool = JSBool;
   exports.JSNull = JSNull;
   exports.JSIndexable = JSIndexable;
   exports.JSMutableIndexable = JSMutableIndexable;
   exports.JSObject = JSObject;
   exports.JavaScriptObject = JavaScriptObject;
   exports.PlainJavaScriptObject = PlainJavaScriptObject;
   exports.UnknownJavaScriptObject = UnknownJavaScriptObject;
 })(_interceptors || (_interceptors = {}));