[CMake] CMake --debug-trycompile option breaking tests

[Clifford Yapp]

We're seeing a problem when trying to run a cmake configuration using
both the TestBigEndian.cmake macro and the --debug-trycompile command
line option for CMake:

Sometimes we're getting

CMake Error at TestBigEndian.cmake:44 (MESSAGE):
  no suitable type found

Oddly, if I copy the CheckTypeSize macro to our local CMake directory
in the build, we then progress further to:

CMake Error at TestBigEndian.cmake:97 (MESSAGE):
  TEST_BIG_ENDIAN found no result!


I'm seeing a few other indications that whatever --debug-trycompile is
doing, it is messing with the results of various tests - has anybody
else seen this problem?  It would be very handy for us to be able to
preserve the sources from functionality testing to make sure they're
doing what we think they're doing, but so far it looks like trying to
save them with --debug-trycompile is breaking things.

Any help appreciated.  Thanks,

CY