[riscv-port] RFR: 8281632: riscv: Improve interpreter stack banging [v5]

[Yadong Wang]

> With reference to https://bugs.openjdk.java.net/browse/JDK-8072070, there is the same issue on the riscv platform.
>  
> 
> Every time we enter a method in interpreter, we bang a lot of stack ahead for shadow zone checks. I believe this could be made significantly better, e.g. by checking how far away we are from the stack_overflow_limit.
> 
> 
> Hotspot/jdk tier1 passed on unmatched, and all jtreg cases were tested on Qemu without new failures.
> 
> Performed the performance regression test in SPECjvm2008 sunflow, and achieved 17% improvement in the interpreter-only mode.

Yadong Wang has updated the pull request incrementally with one additional commit since the last revision:

  remove redundant white spaces

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Changes:
  - all: https://git.openjdk.java.net/riscv-port/pull/58/files
  - new: https://git.openjdk.java.net/riscv-port/pull/58/files/ea9ad368..859aa7c6

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=riscv-port&pr=58&range=04
 - incr: https://webrevs.openjdk.java.net/?repo=riscv-port&pr=58&range=03-04

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/riscv-port/pull/58.diff
  Fetch: git fetch https://git.openjdk.java.net/riscv-port pull/58/head:pull/58

PR: https://git.openjdk.java.net/riscv-port/pull/58