Update tests.

test/libsolidity/semanticTests/strings/unicode_escapes.sol

@@ -15,6 +15,8 @@ contract C {
         return "\u0024\u00A2\u20AC";
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // oneByteUTF8() -> 0x20, 7, "aaa$aaa"
 // twoBytesUTF8() -> 0x20, 8, "aaa\xc2\xa2aaa"

test/libsolidity/semanticTests/strings/unicode_string.sol

@@ -3,5 +3,7 @@ contract C {
         return "😃, 😭, and 😈";
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // f() -> 0x20, 0x14, "\xf0\x9f\x98\x83, \xf0\x9f\x98\xad, and \xf0\x9f\x98\x88"