RFR: 8336999: Verification for resource area allocated data structures in C2

[Tobias Hartmann]

Similar to [GrowableArrayNestingCheck](https://github.com/openjdk/jdk/blob/master/src/hotspot/share/utilities/growableArray.cpp#L60), we should implement a check for C2's resource allocated data structures that verifies that reallocation happens under the same `ResourceMark` as the original allocation. Otherwise, use-after-free bugs like [JDK-8336095](https://bugs.openjdk.org/browse/JDK-8336095) will lead to memory corruption.

This change adds a [ReallocMark](https://github.com/openjdk/jdk/blob/master/src/hotspot/share/memory/allocation.cpp#L233) to all resource allocated data structures used by C2. I slightly modified it such that it checks the arena and skips verification if the data is not allocated in the resource arena. I also modified the grow methods such that we perform verification even if no reallocation is required. In addition, I changed a few `Unique_Node_List` allocations in vector.cpp from `comp_arena` to resource area allocations because they only have a short lifetime.

While testing, I hit the verification code from:

V  [libjvm.so+0x5c1ceb]  ReallocMark::check(Arena*)+0x7b  (allocation.cpp:244)
V  [libjvm.so+0x6df2da]  Block_Array::grow(unsigned int)+0x1a  (block.cpp:43)
V  [libjvm.so+0xb88679]  PhaseCFG::do_DFS(Tarjan*, unsigned int)+0x159  (block.hpp:72)
V  [libjvm.so+0xb88b6b]  PhaseCFG::build_dominator_tree()+0xab  (domgraph.cpp:74)
V  [libjvm.so+0xd75791]  PhaseCFG::do_global_code_motion()+0x11  (gcm.cpp:1635)
V  [libjvm.so+0x9f4fd4]  Compile::Code_Gen()+0x2a4  (compile.cpp:2949)
V  [libjvm.so+0x9f5f16]  Compile::Compile(ciEnv*, TypeFunc const* (*)(), unsigned char*, char const*, int, bool, bool, DirectiveSet*)+0xba6  (compile.cpp:991)


It's a false positive because the code in `PhaseCFG::build_dominator_tree` pre-grows `PhaseCFG::_blocks` to prevent reallocation before entering the scope of a nested ResourceMark. I think that's bad practice and should be avoided. I changed the code to allocate `_blocks` in a separate arena and removed the pre-growing.

This detects [JDK-8336095](https://bugs.openjdk.org/browse/JDK-8336095) right away, even with `java -Xcomp -version`.

We should revisit the footprint impact of arena allocations in C2 with [JDK-8337015](https://bugs.openjdk.org/browse/JDK-8337015).

Thanks,
Tobias

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

Commit messages:
 - Reverted fix for 8336095
 - Small fix + refactoring
 - First prototype - tier1-3 pass

Changes: https://git.openjdk.org/jdk/pull/20311/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20311&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8336999
  Stats: 56 lines in 14 files changed: 33 ins; 8 del; 15 mod
  Patch: https://git.openjdk.org/jdk/pull/20311.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20311/head:pull/20311

PR: https://git.openjdk.org/jdk/pull/20311