Fix dues to crash when converting a const vector to another vector #1864.

test/test_suite/vector/vector_to_array_fail.c3

@@ -9,5 +9,5 @@ fn void main()
 	int[<*>] z = x;
 	int[<*>] w = y;
 	double[<2>] ww = x;
-	short[<2>] www = y; // #error: implicitly be converted
+	short[<2>] www = y; // #error: Implicitly casting 'int[2]' to 'short[<2>]'
 }

test/test_suite/vector/vector_to_vector_const_fail.c3

@@ -0,0 +1,5 @@
+fn int main(String[] args)
+{
+	const double[4] ONE = { 1.0, 1.0, 1.0, 1.0 };
+	float[<4>] vec4 = ONE; // #error: Implicitly casting 'double[4]' to 'float[<4>]'
+}