filter_compiler_path: added the possibility to narrow search path

Following a comment from Todd, the search path for the files listed in
`filter_compiler_wrappers` can now be narrowed. Anyhow, the function
implementation still makes use of `find`, the rationale being that we
have already seen packages that install artifacts in e.g. architecture
dependent folders. The possibility to have a relative search path might
be a good compromise between the previous approach and the one suggested
in the review.

Also: 'ignore_absent' and 'backup' keyword arguments can be optionally
forwarded to `filter_file`.

var/spack/repos/builtin/packages/hdf5/package.py

@@ -97,7 +97,7 @@ class Hdf5(AutotoolsPackage):
     patch('h5f90global-mult-obj-same-equivalence-same-common-block.patch',
           when='@1.10.1%intel@18')
 
-    filter_compiler_wrappers('h5cc', 'h5c++', 'h5fc')
+    filter_compiler_wrappers('h5cc', 'h5c++', 'h5fc', relative_root='bin')
 
     def url_for_version(self, version):
         url = "https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-{0}/hdf5-{1}/src/hdf5-{1}.tar.gz"

var/spack/repos/builtin/packages/mpich/package.py

@@ -71,7 +71,9 @@ class Mpich(AutotoolsPackage):
     provides('mpi@:3.0', when='@3:')
     provides('mpi@:1.3', when='@1:')
 
-    filter_compiler_wrappers('mpicc', 'mpicxx', 'mpif77', 'mpif90')
+    filter_compiler_wrappers(
+        'mpicc', 'mpicxx', 'mpif77', 'mpif90', 'mpifort', relative_root='bin'
+    )
 
     # fix MPI_Barrier segmentation fault
     # see https://lists.mpich.org/pipermail/discuss/2016-May/004764.html

var/spack/repos/builtin/packages/mvapich2/package.py

@@ -107,7 +107,9 @@ class Mvapich2(AutotoolsPackage):
     depends_on('libpciaccess', when=(sys.platform != 'darwin'))
     depends_on('cuda', when='+cuda')
 
-    filter_compiler_wrappers('mpicc', 'mpicxx', 'mpif77', 'mpif90', 'mpifort')
+    filter_compiler_wrappers(
+        'mpicc', 'mpicxx', 'mpif77', 'mpif90', 'mpifort', relative_root='bin'
+    )
 
     def url_for_version(self, version):
         base_url = "http://mvapich.cse.ohio-state.edu/download"

var/spack/repos/builtin/packages/openmpi/package.py

@@ -228,7 +228,8 @@ class Openmpi(AutotoolsPackage):
         'mpif90-vt-wrapper-data.txt',
         'mpif90-wrapper-data.txt',
         'mpif77-vt-wrapper-data.txt',
-        'mpif77-wrapper-data.txt'
+        'mpif77-wrapper-data.txt',
+        relative_root=os.path.join('share', 'openmpi')
     )
 
     def url_for_version(self, version):

var/spack/repos/builtin/packages/r/package.py

@@ -88,7 +88,9 @@ class R(AutotoolsPackage):
 
     patch('zlib.patch', when='@:3.3.2')
 
-    filter_compiler_wrappers('Makeconf')
+    filter_compiler_wrappers(
+        'Makeconf', relative_root=os.path.join('rlib', 'R', 'etc')
+    )
 
     @property
     def etcdir(self):