RFR 8028347: Rewriter::scan_method asserts with array oob in RT_Baseline

[Coleen Phillimore]

Summary: Fix reversing rewriting for invokespecial (which I broke with 
last checkin)

Ran runtime jtreg tests (including failing tests).   Rerunning 
vm.mlvm.testlist.

open webrev at http://cr.openjdk.java.net/~coleenp/8028347/
bug link https://bugs.openjdk.java.net/browse/JDK-8028347

Thanks,
Coleen