Fix missing dependencies and glibc build failures (#9106)

* bison: Add missing build dependencies

bison also depends on cmp, which is currently not available in Spack.

* help2man: Add missing build dependency

* m4: Fix build with newer versions of glibc

* openssl: Add missing build dependency

openssl's configure script is actually a Perl script.

* texinfo: Add missing perl dependency

* diffutils: New package

* findutils: Fix build with newer versions of glibc

* mvapich2, mpich: Add missing findutils dependency

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

@@ -117,6 +117,7 @@ class Mvapich2(AutotoolsPackage):
         multi=True
     )
 
+    depends_on('findutils', type='build')
     depends_on('bison', type='build')
     depends_on('libpciaccess', when=(sys.platform != 'darwin'))
     depends_on('cuda', when='+cuda')