src/sage: add random distutils comments to libgap files

These probably don't do the right thing, but what they do do is touch
every extension module that links to libgap. This happens to fix the
upgrade path currently broken by the new libgap soname. The sage build
system does not recognize the need to rebuild libgap's consumers, but
if we modify them, it will have to rebuild them anyway.

src/sage/groups/perm_gps/permgroup_element.pyx

@@ -1,3 +1,4 @@
+# distutils: libraries = gap
 r"""
 Permutation group elements
 

src/sage/libs/gap/element.pyx

@@ -1,3 +1,4 @@
+# distutils: libraries = gap gmp m
 """
 GAP element wrapper
 

src/sage/libs/gap/libgap.pyx

@@ -1,3 +1,4 @@
+# distutils: libraries = gap
 """
 Library Interface to GAP
 

src/sage/libs/gap/util.pyx

@@ -1,3 +1,4 @@
+# distutils: libraries = gap
 """
 Utility functions for GAP
 """