Fix cmGeneratorExpression::Preprocess for interleaved inputs.

We can't find both preprocessing expressions at once, because then
the BUILD_INTERFACE will always be favored if both are present, even
if INSTALL_INTERFACE appears first.
Merge topic 'fix-genex-preprocess' into next

1ac45f7 Fix cmGeneratorExpression::Preprocess for interleaved inputs.
Determine C/CXX/Fortran compiler: minor restructuring

No functional changes, only change the way the if()-condition works,
to make it easier to add more cases.

Alex
Determine C/CXX/Fortran compiler: fix indentation

Alex
rename TI_DSP toolchain to TI, since it works also for the ARM compiler

Additionally, look for a special ar and strip

Alex
TI compiler: add automatic detection of prefix and suffixes

The TI cross compilers are named e.g. cl6x or armcl, the accompanying
strip and ar have the same prefixes/suffixes.

Alex
Merge topic 'TI_DSP_to_TI_2' into next

27e6f6e TI compiler: add automatic detection of prefix and suffixes
b301586 rename TI_DSP toolchain to TI, since it works also for the ARM compiler
12b25df Determine C/CXX/Fortran compiler: fix indentation
7baa55a Determine C/CXX/Fortran compiler: minor restructuring