LibJS: Align Instructions as void* and roundup variably sized ones sizes

Both is indeed needed,
the standard alignment would have been 4, but some Instructions, like
Jumps need an alignment of 8

Fixes #12127.

Userland/Libraries/LibJS/Bytecode/Instruction.h

@@ -92,7 +92,7 @@
 
 namespace JS::Bytecode {
 
-class Instruction {
+class alignas(void*) Instruction {
 public:
     constexpr static bool IsTerminator = false;