Relax InterpreterCodelet stub alignment

InterpreterCodelet is aligned by CodeEntryAlignment (CAE) twice. First, the entire stub is aligned, which aligns its data section. Then, the code section in the stub is aligned. Since CAE is usually larger than the size of InterpreterCodelet, we are wasting quite a bit of space for each codelet.

In the extreme cases, like PPC that defaults to CAE=128, we have 16 bytes of codelet data effectively taking 128 bytes!

This can be made better by relaxing the InterpreterCodelet stub alignment to, say, HeapWordSize.