detect_cpu: Fix mips32 detection on mips64

MIPS64 can run MIPS32 code natively, so there is a chance that a mixture
of MIPS64 kernel and MIPS32 userland exists. Before this Meson just
treats such mixture as mips64, because uname -m returns mips64.

So in this case we have to check compiler builtin defines for actual
architecture and CPU in use.

- Also fixes mips64 related detection tests in internaltests:
  Normalize mips64 as mips first, then if __mips64 is defined, return
  mips64 for mips64* machines.

  This is a bit confiusing because normally one would detect if a flag
  of 32-bit target is defined while running on a 64-bit machine. For
  mips64 it is almost just the other way around - we need to detect if
  __mips64 is set to make sure it is a mips64 environment.

Co-Authored-By: Jue Wang <maliya355@outlook.com>

0 files changed, 0 insertions, 0 deletions