Fix C++-generating back end issue with inaccessible or out-of-scope template arguments

[wchilders-nvidia]

This PR fixes #191 and additionally relaxes the accepted regex (used to identify patch numbers for commits) by the pre-push hook in line with the suggested "[GH #XYZ]" in #164.

[mborland]

The one suggestion is a nitpick more than anything. Looks good to me.

[wchilders-nvidia]

The failures seem legitimate, this was submitted by EDG as a late patch for inclusion in the project. It'll need additional work to prevent regressions, e.g. (in xtreme-header-8.sft.rt.tar.gz):

--- Expected Output
+++ Observed Output
@@ -0,0 +1,17 @@
+"/mds/gnu/build/gcc-15.1.0/include/c++/15.1.0/bits/fs_path.h", line 1440: error: expected an identifier
+  extern template __shared_ptr< const filesystem::__cxx11::filesystem_error::_Impl> ;
+                                                                                    ^
+
+"/mds/gnu/build/gcc-15.1.0/include/c++/15.1.0/bits/fs_path.h", line 1440: error: invalid explicit instantiation declaration
+  extern template __shared_ptr< const filesystem::__cxx11::filesystem_error::_Impl> ;
+                  ^
+
+"/mds/gnu/build/gcc-15.1.0/include/c++/15.1.0/bits/fs_dir.h", line 627: error: expected an identifier
+  extern template __shared_ptr< filesystem::__cxx11::recursive_directory_iterator::_Dir_stack> ;
+                                                                                               ^
+
+"/mds/gnu/build/gcc-15.1.0/include/c++/15.1.0/bits/fs_dir.h", line 627: error: invalid explicit instantiation declaration
+  extern template __shared_ptr< filesystem::__cxx11::recursive_directory_iterator::_Dir_stack> ;
+                  ^
+
+4 errors detected in the compilation of "Test_name.c".

[daveedvdv-nvidia]

Merged as a63fc0e