RFR: 8351156: C1: Remove FPU stack support after 32-bit x86 removal

[Aleksey Shipilev]

C1 has the 32-bit x86 specific code that supports x87 FPU stack allocations. With 32-bit x86 port removed, we can clean up those parts. 64-bit x86 does not need x87 FPU, since it is baselined on SSE2 and using XMM registers instead.

There are lots of deeper cleanups possible, this PR focuses on removing the x87 FPU allocation/uses in C1. Note current C1 nomenclature is confusing. On all arches, "FPU" means floating-point _registers_. That is _except_ on x86, where "FPU" means x87 FPU stack, and "XMM" means floating-point registers. This is why we only touch "FPU" code on other architectures only in a light manner. After all 32-bit x86 cleanups land, we might consider renaming "XMM" -> "FPU" in x86 C1 to match the common nomenclature.

Brief tour of changes:
 - FPU stack simulator is not needed anymore, so I removed it and the related infrastructure
 - Lots of 32-bit specific paths that touch x87 FPU registers are pruned
 - Related LIR nodes like `lir_fxch`, `lir_fld`, `lir_fpop_raw` are pruned
 - Simplified the API that is no longer needed, e.g. dropping `pop_fpu_stack`

This PR would likely conflict with some in-flight cleanups, so it would require merges later. Take a look meanwhile.

Additional testing:
 - [x] Linux x86_64 server fastdebug, `tier1`
 - [x] Linux x86_64 server fastdebug, `tier1` + `-XX:TieredStopAtLevel=1`
 - [ ] Linux x86_64 server fastdebug, `all`
 - [ ] Linux x86_64 server fastdebug, `all` + `-XX:TieredStopAtLevel=1`

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Commit messages:
 - Fixing build failures after reg2stack
 - Remove remaining FPU uses in LIRAssembler_x86
 - Touchups
 - Initial fix

Changes: https://git.openjdk.org/jdk/pull/24274/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24274&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8351156
  Stats: 2585 lines in 39 files changed: 0 ins; 2534 del; 51 mod
  Patch: https://git.openjdk.org/jdk/pull/24274.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24274/head:pull/24274

PR: https://git.openjdk.org/jdk/pull/24274