Add support for interfaceID.

test/libsolidity/semanticTests/interfaceID/interfaces.sol

@@ -0,0 +1,67 @@
+interface HelloWorld {
+    function hello() external pure;
+    function world(int) external pure;
+}
+
+interface HelloWorldDerived is HelloWorld {
+    function other() external pure;
+}
+
+interface ERC165 {
+    /// @notice Query if a contract implements an interface
+    /// @param interfaceID The interface identifier, as specified in ERC-165
+    /// @dev Interface identification is specified in ERC-165. This function
+    ///  uses less than 30,000 gas.
+    /// @return `true` if the contract implements `interfaceID` and
+    ///  `interfaceID` is not 0xffffffff, `false` otherwise
+    function supportsInterface(bytes4 interfaceID) external view returns (bool);
+}
+
+contract Test {
+    bytes4 public ghello_world_interfaceId = type(HelloWorld).interfaceId;
+    bytes4 public ERC165_interfaceId = type(ERC165).interfaceId;
+
+    function hello() public pure returns (bytes4 data){
+        HelloWorld i;
+        return i.hello.selector;
+    }
+
+    function world() public pure returns (bytes4 data){
+        HelloWorld i;
+        return i.world.selector;
+    }
+
+    function hello_world() public pure returns (bytes4 data){
+        // HelloWorld i;
+        // return i.hello.selector ^ i.world.selector; // = 0xc6be8b58
+        return 0xc6be8b58;
+    }
+
+    function hello_world_interfaceId() public pure returns (bytes4 data){
+        return type(HelloWorld).interfaceId;
+    }
+
+    function other() public pure returns (bytes4 data){
+        HelloWorldDerived i;
+        return i.other.selector;
+    }
+
+    function hello_world_derived_interfaceId() public pure returns (bytes4 data){
+        return type(HelloWorldDerived).interfaceId;
+    }
+}
+
+// ====
+// compileViaYul: also
+// ----
+// hello() -> left(0x19ff1d21)
+// world() -> left(0xdf419679)
+//
+// ERC165_interfaceId() -> left(0x01ffc9a7)
+//
+// hello_world()              -> left(0xc6be8b58)
+// hello_world_interfaceId()  -> left(0xc6be8b58)
+// ghello_world_interfaceId() -> left(0xc6be8b58)
+//
+// other() -> left(0x85295877)
+// hello_world_derived_interfaceId() -> left(0x85295877)