RFR: 8256025: AArch64: MachCallRuntimeNode::ret_addr_offset() is incorrect for stub calls [v2]

[Nick Gasson]

> The PR for JDK-8254231 introduces a new assertion in opto/output.cpp to
> check the current instruction offset against the offset of the call
> return address reported by ret_addr_offset(). This fails on AArch64
> because MachCallRuntimeNode::ret_addr_offset() claims four instructions
> are generated for a stub call (far branch) but actually it's just
> one (blr to stub or trampoline).
> 
> Tested tier1.

Nick Gasson has updated the pull request incrementally with one additional commit since the last revision:

  Fix comment blr->bl

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1138/files
  - new: https://git.openjdk.java.net/jdk/pull/1138/files/1570be1e..b934df8e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1138&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1138&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1138.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1138/head:pull/1138

PR: https://git.openjdk.java.net/jdk/pull/1138