bugfix: hunspell: add missing gettext dependency (#12347)

* hunspell: write autoreconf method to triage error

This commit fixes the error described in GitHub issue
`AutotoolsPackage` class attempts to call `libtoolize`, which doesn't
exist on macOS systems that externally install `libtool` in Spack via
Homebrew -- Homebrew installzes GNU libtoolize as `glibtoolize`.

The fix is to call `autoreconf` only, and GitHub pull request #12344
makes this change in
AutotoolsPackage (https://github.com/spack/spack/pull/12344). However,
while waiting for that pull request to be merged, overriding the
`autoreconf` method achieves the same result for a self-contained
fix. This self-contained fix is necessary to fix a dependency bug in
the `hunspell` package.

* hunspell: add missing gettext dependency

* hunspell: add version 1.7.0

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

@@ -12,9 +12,17 @@ class Hunspell(AutotoolsPackage):
     homepage = "http://hunspell.github.io/"
     url      = "https://github.com/hunspell/hunspell/archive/v1.6.0.tar.gz"
 
+    version('1.7.0', sha256='57be4e03ae9dd62c3471f667a0d81a14513e314d4d92081292b90435944ff951')
     version('1.6.0', '047c3feb121261b76dc16cdb62f54483')
 
     depends_on('autoconf', type='build')
     depends_on('automake', type='build')
     depends_on('libtool',  type='build')
     depends_on('m4',       type='build')
+    depends_on('gettext')
+
+    # TODO: If https://github.com/spack/spack/pull/12344 is merged, this
+    # method is unnecessary.
+    def autoreconf(self, spec, prefix):
+        autoreconf = which('autoreconf')
+        autoreconf('-fiv')