RFR: 8265327: Remove check_safepoint_and_suspend_for_native_trans() [v3]

[Patricio Chilano Mateo]

> Hi,
> 
> Please review this small fix. Method check_safepoint_and_suspend_for_native_trans() can just be removed and the code moved directly to check_special_condition_for_native_trans(). The other caller, transition_from_native(), can also just call SafepointMechanism::process_if_requested_with_exit_check() after transitioning to _thread_in_native_trans. Since that removes the only caller of is_suspend_after_native() I also removed it. 
> I also made a small fix to has_special_runtime_exit_condition(). The compilers were generating three different comparisons for _suspend_flags instead of combining the constant values and doing a single one (I checked this with gcc 10.2 on linux and clang-12 on macos). The extra code was preventing inlining on some cases. For instance, on a Linux release build with gcc 10.2, for the ThreadInVMfromNative constructor, transition_from_native() was being inlined but not process_if_requested_with_exit_check(), so we still required a call for the fast case. The small change to has_special_runtime_exit_condition() fixed that. 
> Tested in mach5 tiers1-2.
> 
> Thanks,
> 
> Patricio

Patricio Chilano Mateo has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains five commits:

 - Merge branch 'master' into 8265327
 - fix typo in comment for check_special_condition_for_native_trans
 - fix has_special_runtime_exit_condition() to favor inlining
 - remove is_suspend_after_native()
 - v1

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Changes: https://git.openjdk.java.net/jdk/pull/3548/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3548&range=02
  Stats: 37 lines in 3 files changed: 4 ins; 23 del; 10 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3548.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3548/head:pull/3548

PR: https://git.openjdk.java.net/jdk/pull/3548