Fix #269

Shorten most primitives where possible. Also optimize some edge cases.

test/compress/issue-269.js

@@ -0,0 +1,68 @@
+issue_269_1: {
+	options = {unsafe: true};
+	input: {
+		f(
+			String(x),
+			Number(x),
+			Boolean(x),
+
+			String(),
+			Number(),
+			Boolean()
+		);
+	}
+	expect: {
+		f(
+			x + '', +x, !!x,
+			'', 0, false
+		);
+	}
+}
+
+issue_269_dangers: {
+	options = {unsafe: true};
+	input: {
+		f(
+			String(x, x),
+			Number(x, x),
+			Boolean(x, x)
+		);
+	}
+	expect: {
+		f(String(x, x), Number(x, x), Boolean(x, x));
+	}
+}
+
+issue_269_in_scope: {
+	options = {unsafe: true};
+	input: {
+		var String, Number, Boolean;
+		f(
+			String(x),
+			Number(x, x),
+			Boolean(x)
+		);
+	}
+	expect: {
+		var String, Number, Boolean;
+		f(String(x), Number(x, x), Boolean(x));
+	}
+}
+
+strings_concat: {
+	options = {unsafe: true};
+	input: {
+		f(
+			String(x + 'str'),
+			String('str' + x),
+			String(x + 5)
+		);
+	}
+	expect: {
+		f(
+			x + 'str',
+			'str' + x,
+			x + '5'
+		);
+	}
+}