[SMTChecker] Fix literal string type mismatch

test/libsolidity/smtCheckerTests/complex/slither/const_state_variables.sol

@@ -53,9 +53,6 @@ contract MyConc{
 // ----
 // Warning: (773-792): This declaration shadows an existing declaration.
 // Warning: (1009-1086): Function state mutability can be restricted to view
-// Warning: (327-332): Assertion checker does not yet support the type of this literal (literal_string "abc").
-// Warning: (353-358): Assertion checker does not yet support the type of this literal (literal_string "xyz").
-// Warning: (834-839): Assertion checker does not yet support the type of this literal (literal_string "abc").
 // Warning: (874-879): Underflow (resulting value less than 0) happens here.
 // Warning: (874-879): Overflow (resulting value larger than 2**256 - 1) happens here.
 // Warning: (985-1002): Overflow (resulting value larger than 2**256 - 1) happens here.

test/libsolidity/smtCheckerTests/complex/slither/external_function.sol

@@ -83,7 +83,6 @@ contract InternalCall {
 // Warning: (1144-1206): Function state mutability can be restricted to pure
 // Warning: (1212-1274): Function state mutability can be restricted to pure
 // Warning: (1280-1342): Function state mutability can be restricted to pure
-// Warning: (799-811): Assertion checker does not yet support the type of this literal (literal_string "helloTwo()").
 // Warning: (782-813): Type conversion is not yet fully supported and might yield false positives.
 // Warning: (771-814): Assertion checker does not yet implement this type of function call.
 // Warning: (825-830): Assertion checker does not yet support the type of this variable.

test/libsolidity/smtCheckerTests/functions/abi_encode_functions.sol

@@ -6,7 +6,5 @@ contract C {
 }
 // ----
 // Warning: (31-64): Experimental features are turned on. Do not use experimental features on live deployments.
-// Warning: (173-175): Assertion checker does not yet support the type of this literal (literal_string "").
 // Warning: (162-176): Assertion checker does not yet implement this type of function call.
-// Warning: (196-202): Assertion checker does not yet support the type of this literal (literal_string "7?8r").
 // Warning: (178-203): Assertion checker does not yet implement this type of function call.

test/libsolidity/smtCheckerTests/types/string_2.sol

@@ -8,4 +8,3 @@ contract C
 }
 // ----
 // Warning: (76-91): Unused local variable.
-// Warning: (94-107): Assertion checker does not yet support the type of this literal (literal_string "Hello World").

test/libsolidity/smtCheckerTests/types/string_literal_assignment_1.sol

@@ -0,0 +1,13 @@
+pragma experimental SMTChecker;
+
+contract C {
+	function f(bytes32 _x) public pure {
+		require(_x == "test");
+		bytes32 y = "test";
+		bytes16 z = "testz";
+		assert(_x == y);
+		assert(_x == z);
+	}
+}
+// ----
+// Warning: (175-190): Assertion violation happens here

test/libsolidity/smtCheckerTests/types/string_literal_assignment_2.sol

@@ -0,0 +1,12 @@
+pragma experimental SMTChecker;
+
+contract C {
+	function f(bytes32 _x) public pure {
+		require(_x == "test");
+		(bytes32 y, bytes16 z) = ("test", "testz");
+		assert(_x == y);
+		assert(_x == z);
+	}
+}
+// ----
+// Warning: (176-191): Assertion violation happens here

test/libsolidity/smtCheckerTests/types/string_literal_assignment_3.sol

@@ -0,0 +1,14 @@
+pragma experimental SMTChecker;
+
+contract C {
+	function f(bytes32 _x) public pure {
+		require(_x == "test");
+		bytes32 y;
+		bytes16 z;
+		(y, z) = ("test", "testz");
+		assert(_x == y);
+		assert(_x == z);
+	}
+}
+// ----
+// Warning: (186-201): Assertion violation happens here

test/libsolidity/smtCheckerTests/types/string_literal_assignment_4.sol

@@ -0,0 +1,18 @@
+pragma experimental SMTChecker;
+
+contract C {
+	function g() internal pure returns (bytes32, bytes16) {
+		return ("test", "testz");
+	}
+
+	function f(bytes32 _x) public pure {
+		require(_x == "test");
+		bytes32 y;
+		bytes16 z;
+		(y, z) = g();
+		assert(_x == y);
+		assert(_x == z);
+	}
+}
+// ----
+// Warning: (261-276): Assertion violation happens here

test/libsolidity/smtCheckerTests/types/string_literal_assignment_5.sol

@@ -0,0 +1,16 @@
+pragma experimental SMTChecker;
+
+contract C {
+	function g() internal pure returns (bytes32, bytes16) {
+		return ("test", "testz");
+	}
+
+	function f(bytes32 _x) public pure {
+		require(_x == "test");
+		(bytes32 y, bytes16 z) = g();
+		assert(_x == y);
+		assert(_x == z);
+	}
+}
+// ----
+// Warning: (251-266): Assertion violation happens here

test/libsolidity/smtCheckerTests/types/string_literal_comparison_1.sol

@@ -0,0 +1,13 @@
+pragma experimental SMTChecker;
+
+contract C {
+	function f(bytes32 _x) public pure {
+		require(_x == "test");
+		bytes32 y = _x;
+		bytes32 z = _x;
+		assert(z == "test");
+		assert(y == "testx");
+	}
+}
+// ----
+// Warning: (170-190): Assertion violation happens here

test/libsolidity/smtCheckerTests/types/string_literal_comparison_2.sol

@@ -0,0 +1,13 @@
+pragma experimental SMTChecker;
+
+contract C {
+	function f(bytes32 _x) public pure {
+		require(_x != "test");
+		bytes32 y = _x;
+		bytes32 z = _x;
+		assert(z == "test");
+		assert(y != "testx");
+	}
+}
+// ----
+// Warning: (147-166): Assertion violation happens here

test/libsolidity/smtCheckerTests/verification_target/simple_assert_with_require_message.sol

@@ -6,4 +6,3 @@ contract C {
 	}
 }
 // ----
-// Warning: (97-125): Assertion checker does not yet support the type of this literal (literal_string "Input number is too large.").