RFR: 8343789: Move mutable nmethod data out of CodeCache [v14]

[Boris Ulasevich]

> This change relocates mutable data (such as relocations, metadata, jvmci data) from the nmethod. The change follows the recent PR #18984, which relocated immutable nmethod data out of the CodeCache.
> 
> OOPs was initially moved to a new mutable data blob, but then moved back to nmethod due to performance issues on dacapo benchmarks on aarch with ShenandoagGC (why Shenandoah: it is the only GC with supports_instruction_patching=false - it requires loading from the oops table in compiled code, which takes three instructions for a remote data).
> 
> Although performance is not the main focus, testing on AArch64 CPUs, where code density plays a significant role, has shown a 1–2% performance improvement in specific scenarios, such as the CodeCacheStress test and the Renaissance Dotty benchmark.
> 
> The numbers. Immutable data constitutes **~30%** on the nmehtod. Mutable data constitutes **~8%** of nmethod. Example (statistics collected on the CodeCacheStress benchmark):
> - nmethod_count:134000, total_compilation_time: 510460ms
> - total allocation time malloc_mutable/malloc_immutable/CodeCache_alloc: 62ms/114ms/6333ms,
> - total allocation size (mutable/immutable/nmentod): 64MB/192MB/488MB
> 
> Functional testing: jtreg on arm/aarch/x86.
> Performance testing: renaissance/dacapo/SPECjvm2008 benchmarks.
> 
> Alternative solution (see comments): In the future, relocations can be moved to _immutable_data.

Boris Ulasevich has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 15 commits:

 - swap matadata and jvmci data in outputs according to data layout
 - cleanup
 - returning oops back to nmethods. jtreg: Ok, performance: Ok. todo: cleanup
 - Address review comments: cleanup, move fields to avoid padding, fix CodeBlob purge to call os::free, fix nmethod::print, update Layout description
 - add a separate adrp_movk function to to support targets located more than 4GB away
 - Force the use of movk in combination with adrp and ldr instructions to address scenarios
   where os::malloc allocates buffers beyond the typical ±4GB range accessible with adrp
 - Fixing TestFindInstMemRecursion test fail with XX:+StressReflectiveCode option:
   _relocation_size can exceed 64Kb, in this case _metadata_offset do not fit into int16.
   Fix: use _oops_size int16 field to calculate metadata offset
 - removing dead code
 - a bit of cleanup and addressing review suggestions
 - rework movoop for not_supports_instruction_patching case: correcting in ldr_constant and relocations fixup
 - ... and 5 more: https://git.openjdk.org/jdk/compare/cfab88b1...bc8c590c

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Changes: https://git.openjdk.org/jdk/pull/21276/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21276&range=13
  Stats: 192 lines in 7 files changed: 87 ins; 37 del; 68 mod
  Patch: https://git.openjdk.org/jdk/pull/21276.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21276/head:pull/21276

PR: https://git.openjdk.org/jdk/pull/21276