RFR: 8307352: AARCH64: Improve itable_stub

[Boris Ulasevich]

This is a change for AARCH similar to https://github.com/openjdk/jdk/pull/13460 

The change replaces two separate iterations over the itable with a new algorithm consisting of two loops. First, we look for a match with resolved_klass, checking for a match with holder_klass along the way. Then we continue iterating (not starting over) the itable using the second loop, checking only for a match with holder_klass.

InterfaceCalls openjdk benchmark performance results on A53, A72, Neoverse N1 and V1 micro-architectures:


Cortex-A53 (Pi 3 Model B Rev 1.2)

test1stInt2Types    37.5      37.358     0.38
test1stInt3Types   160.166   148.04      8.19
test1stInt5Types   158.131   147.955     6.88
test2ndInt2Types    52.634    53.291    -1.23
test2ndInt3Types   201.39    181.603    10.90
test2ndInt5Types   195.722   176.707    10.76
testIfaceCall      157.453   140.498    12.07
testIfaceExtCall   175.46    154.351    13.68
testMonomorphic     32.052    32.039     0.04
                                 AVG:    6.85

Cortex-A72 (Pi 4 Model B Rev 1.2)

test1stInt2Types    27.4796   27.4738    0.02
test1stInt3Types    66.0085   64.9374    1.65
test1stInt5Types    67.9812   66.2316    2.64
test2ndInt2Types    32.0581   32.062    -0.01
test2ndInt3Types    68.2715   65.6643    3.97
test2ndInt5Types    68.1012   65.8024    3.49
testIfaceCall       64.0684   64.1811   -0.18
testIfaceExtCall    91.6226   81.5867   12.30
testMonomorphic     26.7161   26.7142    0.01
                                 AVG:    2.66

Neoverse N1 (m6g.metal)

test1stInt2Types     2.9104    2.9086    0.06
test1stInt3Types    10.9642   10.2909    6.54
test1stInt5Types    10.9607   10.2856    6.56
test2ndInt2Types     3.3410    3.3478   -0.20
test2ndInt3Types    12.3291   11.3089    9.02
test2ndInt5Types    12.328    11.2704    9.38
testIfaceCall       11.0598   10.3657    6.70
testIfaceExtCall    13.0692   11.2826   15.84
testMonomorphic      2.2354    2.2341    0.06
                                 AVG:    6.00

Neoverse V1 (c7g.2xlarge)

test1stInt2Types    2.2317     2.2320   -0.01
test1stInt3Types    6.6884     6.1911    8.03
test1stInt5Types    6.7334     6.2193    8.27
test2ndInt2Types    2.4002     2.4013   -0.04
test2ndInt3Types    7.9603     7.0372   13.12
test2ndInt5Types    7.9532     7.0474   12.85
testIfaceCall       6.7028     6.3272    5.94
testIfaceExtCall    8.3253     6.9416   19.93
testMonomorphic     1.2446     1.2544   -0.79
                                 AVG:    7.48 


Testing: jtreg tier1-3, release & fastdebug

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

Commit messages:
 - restore comments, fix pseudocode, replace CSEL
 - build fix: in_bytes
 - align to x86 impl
 - 8307352: AARCH64: Improve itable_stub

Changes: https://git.openjdk.org/jdk/pull/13792/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13792&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8307352
  Stats: 133 lines in 3 files changed: 117 ins; 13 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/13792.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13792/head:pull/13792

PR: https://git.openjdk.org/jdk/pull/13792