fixes private named constructors

test/codegen/expect/constructors.js

 var constructors;
 (function(exports) {
   'use strict';
   class A extends core.Object {
   }
   class B extends core.Object {
     B() {
     }
   }
   class C extends core.Object {
-    C$named() {
+    named() {
     }
   }
   dart.defineNamedConstructor(C, 'named');
   class C2 extends C {
-    C2$named() {
-      super.C$named();
+    named() {
+      super.named();
     }
   }
   dart.defineNamedConstructor(C2, 'named');
   class D extends core.Object {
     D() {
     }
-    D$named() {
+    named() {
     }
   }
   dart.defineNamedConstructor(D, 'named');
   class E extends core.Object {
     E(name) {
       this.name = name;
     }
   }
   class F extends E {
     F(name) {
       super.E(name);
     }
   }
   class G extends core.Object {
     G(p1) {
       if (p1 === void 0)
         p1 = null;
     }
   }
   class H extends core.Object {
     H(opts) {
       let p1 = opts && 'p1' in opts ? opts.p1 : null;
     }
   }
   class I extends core.Object {
     I() {
       this.name = 'default';
     }
-    I$named(name) {
+    named(name) {
       this.name = name;
     }
   }
   dart.defineNamedConstructor(I, 'named');
   class J extends core.Object {
     J() {
       this.initialized = true;
       this.nonInitialized = null;
     }
   }
   class K extends core.Object {
     K() {
       this.s = 'a';
     }
-    K$withS(s) {
+    withS(s) {
       this.s = s;
     }
   }
   dart.defineNamedConstructor(K, 'withS');
   class L extends core.Object {
     L(foo) {
       this.foo = foo;
     }
   }
   class M extends L {
-    M$named(x) {
+    named(x) {
       super.L(dart.notNull(x) + 42);
     }
   }
   dart.defineNamedConstructor(M, 'named');
   class N extends M {
-    N$named(y) {
-      super.M$named(dart.notNull(y) + 100);
+    named(y) {
+      super.named(dart.notNull(y) + 100);
     }
   }
   dart.defineNamedConstructor(N, 'named');
   class P extends N {
     P(z) {
-      super.N$named(dart.notNull(z) + 9000);
+      super.named(dart.notNull(z) + 9000);
     }
-    P$foo(x) {
+    foo(x) {
       this.P(dart.notNull(x) + 42);
     }
-    P$bar() {
-      this.P$foo(1);
+    bar() {
+      this.foo(1);
     }
   }
   dart.defineNamedConstructor(P, 'foo');
   dart.defineNamedConstructor(P, 'bar');
   // Exports:
   exports.A = A;
   exports.B = B;
   exports.C = C;
   exports.C2 = C2;
   exports.D = D;
   exports.E = E;
   exports.F = F;
   exports.G = G;
   exports.H = H;
   exports.I = I;
   exports.J = J;
   exports.K = K;
   exports.L = L;
   exports.M = M;
   exports.N = N;
   exports.P = P;
 })(constructors || (constructors = {}));