RFR(S): 8216376: [PPC64] Possibly unreliable stack frame resizing in template interpreter

[Doerr, Martin]

Hi,

we recently noticed stack corruption while testing JDK-8216060. The issue was not directly in the new code, but it didn't work with the current handling of the interpreter stack frames which is very error-prone at a few places.
I'd like to improve these places. At least one of them even seems to be unreliable in the current implementation.

Bug with some more background information:
https://bugs.openjdk.java.net/browse/JDK-8216376

My proposal to fix it:
http://cr.openjdk.java.net/~mdoerr/8216376_PPC64_frame_resizing/webrev.00/

Please review.

Best regards,
Martin