Add macro compiler_repository to have early access to compiler name

This can be used to disable multibuilds for certain compilers.

mpcdf_common.py

@@ -409,10 +409,12 @@ def mpcdf_setup_repositories(api_url, project, distribution=None, parent=None, p
         repo("System", ("distributions", distribution))
 
     for compiler in compilers + pgis:
-        repo(compiler, (project, "System"), compiler=True)
+        repo(compiler, (project, "System"), compiler=True,
+             compiler_repository=compiler)
 
         for mpi in filter(partial(valid_mpi, compiler), mpis):
-            repo(mpi + "_" + compiler, (project, compiler), mpi=True, mpi_repository=mpi)
+            repo(mpi + "_" + compiler, (project, compiler), mpi=True,
+                 mpi_repository=mpi, compiler_repository=compiler)
 
     for cuda in cudas:
         for compiler in filter(partial(valid_cuda, cuda), compilers):