RFR: 8267098: AArch64: C1 StubFrames end confusingly

[Alan Hayward]

On Fri, 14 May 2021 11:28:45 GMT, Alan Hayward <github.com+4146708+a74nh at openjdk.org> wrote:

> For many of the stub frames, a leave/ret is generated after the stub has
> already branched or returned. This is confusing. For these cases, replace
> the superfluous code with a should_not_reach_here
> 
> For handle excception, instead of storing return from the exception
> handler on the stack, it can be moved directly into lr, replacing a store and
> load with a single move. (If/when PAC support is implemented, then this store
> would also have to be signed).

*Restored the code writing return value to stack
*Added enum.

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

PR: https://git.openjdk.java.net/jdk/pull/4030