Add patch to allow PGI to build Bison (#3044)

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

@@ -35,6 +35,8 @@ class Bison(AutotoolsPackage):
 
     version('3.0.4', 'a586e11cd4aff49c3ff6d3b6a4c9ccf8')
 
-    depends_on("m4", type='build')
+    depends_on('m4', type='build')
+
+    patch('pgi.patch', when='@3.0.4')
 
     build_directory = 'spack-build'

var/spack/repos/builtin/packages/bison/pgi.patch

@@ -0,0 +1,10 @@
+--- a/lib/config.in.h
++++ b/lib/config.in.h
+@@ -2182,6 +2182,7 @@
+       ? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
+       : (199901L <= __STDC_VERSION__ \
+          && !defined __HP_cc \
++         && !defined __PGI \
+          && !(defined __SUNPRO_C && __STDC__))) \
+      && !defined _GL_EXTERN_INLINE_STDHEADER_BUG)
+ # define _GL_INLINE inline