Update tests.

test/libsolidity/semanticTests/various/cross_contract_types.sol

@@ -13,5 +13,7 @@ contract Test {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // f() -> 3

test/libsolidity/semanticTests/various/memory_overwrite.sol

@@ -6,5 +6,7 @@ contract C {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // f() -> 0x20, 5, "b23a5"

test/libsolidity/semanticTests/various/negative_stack_height.sol

@@ -58,6 +58,7 @@ contract C {
         )
     {}
 }
-
+// ====
+// compileViaYul: false
 // ----
 // constructor() ->