[Bug target/68263] Vector "*mov<mode>_internal" fails to handle misaligned load/store from reload

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68263

--- Comment #10 from Uroš Bizjak <ubizjak at gmail dot com> ---
Created attachment 36693
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36693&action=edit
Alternative patch

Alternative patch that does a couple of things:
- always defines BIGGEST_ALIGNMENT to 32 for TARGET_IAMCU
- changes "misaligned_operand" to always use natural alignment of the operand
- adds TARGET_IAMCU to generate unaligned vector load/store insns
- fixes ix86_legitimate_combined_insn to consider ssememalign value

The patch regresses sse-1.c (a very delicate test), where it generates slightly
unoptimal, but still correct code.

HJ, can you please test the patch for IAMCU, also with AVX target?