functions taking calldata args should be assignable to function pointers of same type

test/libsolidity/semanticTests/functionTypes/external_functions_with_calldata_args_assigned_to_function_pointers_with_memory_type.sol

@@ -0,0 +1,10 @@
+contract C {
+    function g(string calldata) external returns (bool) { return true; }
+
+    function main() external returns (bool) {
+        function (string memory) external returns (bool) ptr = this.g;
+        return ptr("testString");
+    }
+}
+// ----
+// main() -> true

test/libsolidity/syntaxTests/functionTypes/external_functions_with_calldata_args_assigned_to_function_pointers_of_same_type.sol

@@ -0,0 +1,14 @@
+contract C {
+    function f(function (string calldata) external) external {}
+    function g(string calldata) external {}
+
+    function main() external {
+        function (string calldata) external ptr = this.g;
+        abi.encodeCall(this.f, (this.g));
+        this.f(this.g);
+    }
+}
+// ----
+// TypeError 9574: (161-209): Type function (string memory) external is not implicitly convertible to expected type function (string calldata) external.
+// TypeError 5407: (242-250): Cannot implicitly convert component at position 0 from "function (string memory) external" to "function (string calldata) external".
+// TypeError 9553: (268-274): Invalid type for argument in function call. Invalid implicit conversion from function (string memory) external to function (string calldata) external requested.

test/libsolidity/syntaxTests/functionTypes/external_functions_with_calldata_args_assigned_to_function_pointers_with_memory_type.sol

@@ -0,0 +1,9 @@
+contract C {
+    function g(string calldata) external {}
+
+    function main() view external {
+        function (string memory) external ptr = this.g;
+        ptr;
+    }
+}
+// ----

test/libsolidity/syntaxTests/functionTypes/internal_functions_with_calldata_args_assigned_to_function_pointers_of_same_type.sol

@@ -0,0 +1,9 @@
+contract C {
+    function g(bytes calldata b) pure internal {}
+
+    function main() pure external {
+        function (bytes calldata) internal ptr = g;
+        ptr;
+    }
+}
+// ----