improve clang static analyzer docs further
Discussion at https://redmine.gromacs.org/issues/2162#note-4 and thread suggests we can do better at documenting how to do a manual static-analyzer build.
#1 Updated by Szilárd Páll about 3 years ago
Might want to document expected outcome, which clang versions have been tried with which cmake options.
For the record, in my brief tests related to 2162, current mater builds seem to work fine (1-2 warnings to fix IIRC) with clang 3.9/4.0 with all intra-node parallelization options (haven't tried lib MPI), but in release mode there are a large number of extra warnings.