to allow explicit grouping of hot functions into similar code
sections upon link-time. Should decrease TLB misses (iff the code-
section is really too large)...
Candidates for __opal_attribute_hot__ are MPI_Isend MPI_Irecv,
MPI_Wait, MPI_Waitall
Candidates for __opal_attribute_cold__ are MPI_Init, MPI_Finalize and
MPI_Abort...
This commit was SVN r18421.