RFR: 8292694: x86_64 c2i/i2c adapters may use more stack space than necessary

[Dean Long]

On Fri, 26 Aug 2022 03:08:20 GMT, Dean Long <dlong at openjdk.org> wrote:

> The c2i adapter includes the return address in the alignment calculation, making %rsp always mis-aligned according to the ABI.
> 
> The i2c adapter aligns "extrawords" even though %rsp is aligned later, and the incoming stack is not guaranteed to be aligned.

I included generate_Continuation_doYield_entry() changes by mistake.  I will revert those.

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PR: https://git.openjdk.org/jdk/pull/10034