The conversion of a move pattern where both operands are AX_REG
should be prevented.

2022-09-01  Uroš Bizjak  <ubizjak@gmail.com>

gcc/ChangeLog:

    PR target/106707
    * config/i386/i386.md (moves to/from AX_REG into xchg peephole2):
    Do not convert a move pattern where both operands are AX_REG.

gcc/testsuite/ChangeLog:

    PR target/106707
    * gcc.target/i386/pr106707.c: New test.

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.

Pushed to master.

Uros.