RFR: 8145438: Guarantee failures since 8144028: Use AArch64 bit-test instructions in C2

[Andrew Haley]

This patch touches shared code, so I need a sponsor to push it.

The AArch64 bit-test instructions are limited to a 32k displacement.
In some fairly unusual circumstances the range can exceed this, so we
get a compile-time failure.  This patch implement long and short
variants of the patterns.

The shared code I changed is in adlc.  The problem there is that when
we search for short and long variants of a branch we do not consider
the predicates.  It makes no sense at all for short and long variants
to have different predicates, so suspect this is a bug in adlc.

http://cr.openjdk.java.net/~aph/8145438

Thanks,

Andrew.