RFR (S) 8144518: ClassVerboseTest crashes on Windows

[Coleen Phillimore]

Summary: simplify Bytecode_tableswitch code so windows doesn't generate 
bad code for it.

open webrev at http://cr.openjdk.java.net/~coleenp/8144518.01/webrev
bug link https://bugs.openjdk.java.net/browse/JDK-8144518

Verified generated code does not have sign extended value that is 
subtracted, giving the wrong offset.  Ran all rbt nightly tests. Ran 
some -Xcomp tests.

See more info in bug https://bugs.openjdk.java.net/browse/JDK-8171968

Thanks,
Coleen