[CMake] how to find out the compiler ID of a compiler which doesn't link

[Alexander Neundorf]

Hi,

it seems the IAR C/C++ compiler for AVR cannot generate executables, but only 
object files, and the linker has to be called explcitely on the generated 
object files:
ftp://ftp.iar.se/WWWfiles/avr32/guides/ocavr32.pdf

Which says:
iccavr32 myfile.c
xlink myfile.r82 -s __program_start -f lnkavr32.xcl

Can this be made to work with the compiler ID detection in cmake via compiling 
a source file or is the only chance to use the new 
CMAKE_DETERMINE_COMPILER_ID_VENDOR() function ?

Alex