* Rework cmakery:
* detect rocm/hip/rocshmem better, make sure that ROCM_PATH and
ROCM_ROOT don't conflict and are taken by default
* add /opt/rocm as a fallback when nothing else found
* obtain hipcc in a sanitized way (ensure we use the same logic we
use to later find_package hip)
* factorize redundancies
* export GPU_TARGETS as part of the cmake target for librocshmem,
this helps with a clean error when an application tries to link
with the wrong offload-target flag (rather than a cryptic link error)
* phased out ROCSHMEM_HOME, in favor of rocshmem_ROOT (the cmake
blessed way)
* Remove references to ROCSHMEM_HOME, we prefer ROCSHMEM_ROOT
* Pick CMAKE_PREFIX_PATH method for consistent finding hip/rocm
* Undo this pr using LANGUAGE HIP, maybe later
* Use only rocmcmakebuildtools as recommended from 6.4 onward
[ROCm/rocshmem commit: ee5363be7a]
Aurelien Bouteiller
08d8324f74