Improve support for binding pattern

Including improvements for parameters, variable assignment and
catch parameter.

test/mocha/lhs-expressions.js

@@ -0,0 +1,29 @@
+var assert = require("assert");
+var uglify = require("../../");
+
+describe("Left-hand side expressions", function () {
+    it("Should parse destructuring with const/let/var correctly", function () {
+        var decls = uglify.parse('var {a,b} = foo, { c, d } = bar');
+
+        assert.equal(decls.body[0].TYPE, 'Var');
+        assert.equal(decls.body[0].definitions.length, 2);
+        assert.equal(decls.body[0].definitions[0].name.TYPE, 'Destructuring');
+        assert.equal(decls.body[0].definitions[0].value.TYPE, 'SymbolRef');
+
+        var nested_def = uglify.parse('var [{x}] = foo').body[0].definitions[0];
+
+        assert.equal(nested_def.name.names[0].names[0].TYPE, 'SymbolVar');
+        assert.equal(nested_def.name.names[0].names[0].name, 'x');
+
+        var holey_def = uglify.parse('const [,,third] = [1,2,3]').body[0].definitions[0];
+
+        assert.equal(holey_def.name.names[0].TYPE, 'Hole');
+        assert.equal(holey_def.name.names[2].TYPE, 'SymbolConst');
+
+        var expanding_def = uglify.parse('var [first, ...rest] = [1,2,3]').body[0].definitions[0];
+
+        assert.equal(expanding_def.name.names[0].TYPE, 'SymbolVar');
+        assert.equal(expanding_def.name.names[1].TYPE, 'Expansion');
+        assert.equal(expanding_def.name.names[1].expression.TYPE, 'SymbolVar');
+    });
+});