RFR: 8282204: Use lea instructions for arithmetic operations on x86_64 [v9]

[Jie Fu]

On Fri, 4 Mar 2022 06:59:02 GMT, Quan Anh Mai <duke at openjdk.java.net> wrote:

> The latest change removes the redundant 0x67 prefix from `leal` since it reduces the size of the instruction and without `REX.W` prefix the destination register is 32-bit and according to the manual, the result is:
> 
> > 64-bit effective address is calculated (default address size) and the lower 32 bits of the address are stored in the requested 32-bit register destination.
> 
> which will produce the same result as before. The `prefix(src, dst)` is brought out for uniformity with other instructions, the function itself does not do anything on x86_32 (see assembler_x86.inline.hpp) so it is not a concern.

Did you check cases like 32-bit calculation overflow?
Maybe add a jtreg test to verify the results? 
Thanks.

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PR: https://git.openjdk.java.net/jdk/pull/7560