[riscv-port-jdk17u:riscv-port] RFR: 8276799: Implementation of JEP 422: Linux/RISC-V Port [v2]

[Fei Yang]

On Sat, 18 Feb 2023 03:47:54 GMT, Yadong Wang <yadongwang at openjdk.org> wrote:

>> This PR backports the implementation of RISC-V port into jdk17u. 
>> 
>> It based on the initial implementation of JEP-422 with some modifications for jdk17u:
>> 1.	The initial patch
>>     8276799: Implementation of JEP 422: Linux/RISC-V Port
>> 2.	 remove features that do not belong to jdk17u
>>     revert 8277417: C1 LIR instruction for load-klass
>>     revert 8278387: Implement UseHeavyMonitors consistently
>>     revert 8227369: pd_disjoint_words_atomic() needs to be atomic
>>     revert 8258192: Obsolete the CriticalNatives flag
>>     revert 8281632: riscv: Improve interpreter stack banging
>>     revert 8283364: Intrinsify countPositives
>> 3.	add features that belongs to jdk17u
>>     enable the biased locking
>> 4.	 Wrap modifications to shared code under RISCV and revert changes to other platforms
>> isolate modification to other platforms
>> 5.	Patches for making compilation pass
>> 8282306: os::is_first_C_frame(frame*) crashes on invalid link access
>> 8282477: vmassert(_last_Java_pc == NULL, "already walkable"); fails with async profiler
>
> Yadong Wang has updated the pull request incrementally with one additional commit since the last revision:
> 
>   fix indentation

NOTE: Fix for [JDK-8284068](https://bugs.openjdk.org/browse/JDK-8284068) (https://git.openjdk.java.net/jdk/pull/8055) is also contained in this backport PR.

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PR: https://git.openjdk.org/riscv-port-jdk17u/pull/1