more care around generated names, fixes #60 #82 and #97

test/codegen/expect/names.js

Index: test/codegen/expect/names.js
diff --git a/test/codegen/expect/names.js b/test/codegen/expect/names.js
new file mode 100644
index 0000000000000000000000000000000000000000..ac268d4e3510a09877f867f412fb96342f41d45c
--- /dev/null
+++ b/test/codegen/expect/names.js
@@ -0,0 +1,24 @@
+var names;
+(function(exports) {
+  'use strict';
+  exports.exports = 42;
+  let _foo$ = Symbol('_foo');
+  class Foo extends core.Object {
+    [_foo$]() {
+      return 123;
+    }
+  }
+  // Function _foo: () → dynamic
+  function _foo() {
+    return 456;
+  }
+  // Function main: () → dynamic
+  function main() {
+    core.print(exports.exports);
+    core.print(new Foo()._foo());
+    core.print(_foo());
+  }
+  // Exports:
+  exports.Foo = Foo;
+  exports.main = main;
+})(names || (names = {}));