[foreign-memaccess+abi] RFR: 8275646: Implement optimized upcall stubs on AArch64

[Nick Gasson]

This is a fairly direct port of the X86 code.  The changes to
frame_aarch64 and foreign_globals_aarch64 are identical: perhaps
ForeignGlobals::parse_call_regs_impl() could be moved to shared code?

The X86 version has a call to reinit_heapbase() before the return from
the stub.  I think this is redundant because the heap base register will
be clobbered immediately by the native code?

I hit a really weird bug in release builds where the first few
instructions in the code buffer were overwritten by the fields of
OptimizedEntryBlob.  I think we need to pass sizeof(OptimizedEntryBlob)
instead of sizeof(BufferBlob) as the header_size argument to the
RuntimeBlob constructor (none of the other subclasses of BufferBlob have
extra fields).  I added a header_size argument to BufferBlob's
constructor to thread this through.

I removed the calls to change the W^X state in on_entry/on_exit calls:
in the on_entry case the stub must already be executable because we
called into the VM from there, and for on_exit we need the code to be
executable not writable otherwise we'll get a SIGBUS as soon as we
return to the stub.  The newly added stack tests in TestUpcall hit
JDK-8275584 on MacOS/AArch64 so I've problem-listed that for now.

JMH results from org.openjdk.bench.jdk.incubator.foreign.Upcalls before:


Benchmark                Mode  Cnt     Score    Error  Units
Upcalls.jni_args10       avgt   30   450.417 ?  4.755  ns/op
Upcalls.jni_args5        avgt   30   245.898 ?  3.171  ns/op
Upcalls.jni_blank        avgt   30   195.606 ?  5.459  ns/op
Upcalls.jni_identity     avgt   30   369.788 ? 15.165  ns/op
Upcalls.panama_args10    avgt   30  1253.189 ? 62.261  ns/op
Upcalls.panama_args5     avgt   30   927.101 ? 35.369  ns/op
Upcalls.panama_blank     avgt   30   637.708 ? 11.353  ns/op
Upcalls.panama_identity  avgt   30   697.109 ?  9.971  ns/op


After:


Benchmark                Mode  Cnt    Score    Error  Units
Upcalls.jni_args10       avgt   30  455.304 ? 21.838  ns/op
Upcalls.jni_args5        avgt   30  247.279 ?  2.513  ns/op
Upcalls.jni_blank        avgt   30  194.113 ?  4.317  ns/op
Upcalls.jni_identity     avgt   30  366.145 ?  4.912  ns/op
Upcalls.panama_args10    avgt   30  236.337 ? 11.072  ns/op
Upcalls.panama_args5     avgt   30  223.858 ? 12.345  ns/op
Upcalls.panama_blank     avgt   30  203.631 ?  8.840  ns/op
Upcalls.panama_identity  avgt   30  208.783 ?  9.914  ns/op


Tested tier1 and jdk_foreign on Linux/AArch64 and MacOS/AArch64.

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

Commit messages:
 - 8275646: Implement optimized upcall stubs on AArch64

Changes: https://git.openjdk.java.net/panama-foreign/pull/610/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=610&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8275646
  Stats: 378 lines in 9 files changed: 344 ins; 4 del; 30 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/610.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/610/head:pull/610

PR: https://git.openjdk.java.net/panama-foreign/pull/610