RFR: 8337702: Use new ForwardExceptionNode to call StubRoutines::forward_exception_entry() [v5]

[Vladimir Kozlov]

> Currently C2 uses `TailCall` node when it generates code to forward exception in C2 runtime stubs.
> `StubRoutines::forward_exception_entry()` address is passed as constant and  method pointer is `NULL`: 
> [generateOptoStub.cpp#L258](https://github.com/openjdk/jdk/blob/master/src/hotspot/share/opto/generateOptoStub.cpp#L258)
> 
> On other hand TailCall mach node uses 2 registers as parameter which is hardcoded in `Matcher`: [matcher.cpp#L828](https://github.com/openjdk/jdk/blob/master/src/hotspot/share/opto/matcher.cpp#L828)
> As result we waste two registers to pass constant and NULL.
> 
> Also incorrect relocation is used for such call because the address of `forward_exception` stub passed in register in mach node. When it is converted to `Address` for `jmp` instruction the default `external_word_type` relocation is used when `runtime_call_type` should be used. See discussion in PR [JDK-8337396](https://github.com/openjdk/jdk/pull/20412)
> 
> I added new ideal node `ForwardExceptionNode` to solve these issues. It is similar to `Rethrow` node (which mach node definition I used as template) but I kept it based on `Return` node similar to `TailCall` node.
> 
> Tested tier1-3,stress,xcomp

Vladimir Kozlov has updated the pull request incrementally with one additional commit since the last revision:

  Removed unused variable. Updated copyright year.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20437/files
  - new: https://git.openjdk.org/jdk/pull/20437/files/931e15ce..f08c1728

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20437&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20437&range=03-04

  Stats: 3 lines in 2 files changed: 0 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/20437.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20437/head:pull/20437

PR: https://git.openjdk.org/jdk/pull/20437