[Sol->Yul] Adding util function to copy literal to storage.

Co-authored-by: Daniel Kirchner <daniel@ekpyron.org>

Co-authored-by: chriseth <chris@ethereum.org>

test/libsolidity/semanticTests/array/push/nested_bytes_push.sol

@@ -4,12 +4,17 @@ contract C {
 
     function f() public {
         a.push("abc");
-        a.push("def");
+        a.push("abcdefghabcdefghabcdefghabcdefgh");
+        a.push("abcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefgh");
         assert(a[0][0] == "a");
-        assert(a[1][0] == "d");
+        assert(a[1][31] == "h");
+        assert(a[2][32] == "a");
     }
 }
 // ====
 // compileViaYul: also
 // ----
 // f() ->
+// gas irOptimized: 181480
+// gas legacy: 180320
+// gas legacyOptimized: 180103

test/libsolidity/semanticTests/array/string_literal_assign_to_storage_bytes.sol

@@ -0,0 +1,22 @@
+contract C {
+    bytes public s = "abc";
+    bytes public s1 = "abcd";
+    function f() public {
+        s = "abcd";
+        s1 = "abc";
+    }
+    function g() public {
+        (s, s1) = ("abc", "abcd");
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// s() -> 0x20, 3, "abc"
+// s1() -> 0x20, 4, "abcd"
+// f() ->
+// s() -> 0x20, 4, "abcd"
+// s1() -> 0x20, 3, "abc"
+// g() ->
+// s() -> 0x20, 3, "abc"
+// s1() -> 0x20, 4, "abcd"