Accessors for immutable variables.

test/libsolidity/semanticTests/immutable/complexGetter.sol

@@ -0,0 +1,12 @@
+contract C {
+    function() external returns (uint, uint) immutable public x = this.f;
+    function f() external pure returns (uint, uint) {
+        return (1, 2);
+    }
+
+    function test() external returns (uint, uint) {
+        return this.x()();
+    }
+}
+// ----
+// test() -> 1, 2

test/libsolidity/semanticTests/immutable/getter.sol

@@ -0,0 +1,5 @@
+contract C {
+    uint immutable public x = 1;
+}
+// ----
+// x() -> 1

test/libsolidity/semanticTests/immutable/getter_call_in_constructor.sol

@@ -0,0 +1,17 @@
+contract A {
+    uint immutable public x = 1;
+    uint public y;
+    constructor() public {
+        y = this.x();
+    }
+}
+contract C {
+    function f() public returns (bool) {
+        try new A() { return false; }
+        catch { return true; }
+    }
+}
+// ====
+// EVMVersion: >=tangerineWhistle
+// ----
+// f() -> true