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

[Yadong Wang]

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

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Commit messages:
 - fix copyright year
 - 8282306: os::is_first_C_frame(frame*) crashes on invalid link access
 - 8282477: vmassert(_last_Java_pc == NULL, "already walkable"); fails with async profiler
 - isolate modification to other platforms
 - enable the biased locking
 - revert 8283364: Intrinsify countPositives
 - revert 8281632: riscv: Improve interpreter stack banging
 - revert 8258192: Obsolete the CriticalNatives flag
 - revert 8227369: pd_disjoint_words_atomic() needs to be atomic
 - revert 8278387: Implement UseHeavyMonitors consistently
 - ... and 2 more: https://git.openjdk.org/riscv-port-jdk17u/compare/501a4bf9...47916a22

Changes: https://git.openjdk.org/riscv-port-jdk17u/pull/1/files
 Webrev: https://webrevs.openjdk.org/?repo=riscv-port-jdk17u&pr=1&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8276799
  Stats: 59945 lines in 185 files changed: 59814 ins; 43 del; 88 mod
  Patch: https://git.openjdk.org/riscv-port-jdk17u/pull/1.diff
  Fetch: git fetch https://git.openjdk.org/riscv-port-jdk17u pull/1/head:pull/1

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