RFR: 8281469: aarch64: Improve interpreter stack banging

[Aleksey Shipilev]

This is the AArch64 counterpart of X86 change: https://github.com/openjdk/jdk/commit/3a13425bc9088cbb6d95e1a46248d7eba27fb1a6.

Motivational performance improvements on Raspberry Pi 3:


 Performance counter stats for 'baseline/bin/java -version' (10 runs):

            476.96 msec task-clock                #    1.288 CPUs utilized            ( +-  0.11% )
               166      context-switches          #    0.348 K/sec                    ( +-  0.93% )
                 8      cpu-migrations            #    0.017 K/sec                    ( +-  9.33% )
             2,954      page-faults               #    0.006 M/sec                    ( +-  0.04% )
       560,690,251      cycles                    #    1.176 GHz                      ( +-  0.07% )
       239,068,958      instructions              #    0.43  insn per cycle           ( +-  0.04% )
        30,236,426      branches                  #   63.394 M/sec                    ( +-  0.05% )
         4,145,994      branch-misses             #   13.71% of all branches          ( +-  0.09% )

          0.370225 +- 0.000285 seconds time elapsed  ( +-  0.08% )

 Performance counter stats for 'patched/bin/java -version' (10 runs):

            456.01 msec task-clock                #    1.283 CPUs utilized            ( +-  0.12% )
               156      context-switches          #    0.341 K/sec                    ( +-  0.99% )
                 8      cpu-migrations            #    0.018 K/sec                    ( +-  4.30% )
             2,957      page-faults               #    0.006 M/sec                    ( +-  0.07% )
       536,970,476      cycles                    #    1.178 GHz                      ( +-  0.12% )
       236,527,954      instructions              #    0.44  insn per cycle           ( +-  0.04% )
        30,195,820      branches                  #   66.218 M/sec                    ( +-  0.04% )
         4,128,388      branch-misses             #   13.67% of all branches          ( +-  0.13% )

          0.355460 +- 0.000741 seconds time elapsed  ( +-  0.21% )


SPECjvm2008 with `-Xint`:


Compress: +54%
Serial: +56%


Additional testing:
 - [x] Linux aarch64 fastdebug, `tier1`
 - [x] Linux aarch64 fastdebug, `tier2`
 - [x] Ad-hoc benchmarks

-------------

Commit messages:
 - Unsigned condition codes
 - Do not do str(sp)
 - Fix

Changes: https://git.openjdk.java.net/jdk/pull/8001/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8001&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8281469
  Stats: 40 lines in 1 file changed: 32 ins; 3 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8001.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8001/head:pull/8001

PR: https://git.openjdk.java.net/jdk/pull/8001