PGI workaround for use iso_c_binding (#38)

Fixes #37.

Author: havogt

src/cpp_bindgen/generator.cpp

@@ -154,6 +154,7 @@ namespace cpp_bindgen {
     void generate_fortran_interface(std::ostream &strm, std::string const &module_name) {
         strm << "! This file is generated!\n";
         strm << "module " << module_name << "\n";
+        strm << "use iso_c_binding\n"; // pgi wants to have this
         strm << "implicit none\n";
         strm << "  interface\n\n";
         strm << _impl::get_entities<_impl::fortran_bindings_traits>();

tests/regression/array/bindgen_regression_array.f90

@@ -1,5 +1,6 @@
 ! This file is generated!
 module bindgen_regression_array
+use iso_c_binding
 implicit none
   interface
 

tests/regression/array_gt_legacy/bindgen_regression_array_gt_legacy.f90

@@ -1,5 +1,6 @@
 ! This file is generated!
 module bindgen_regression_array_gt_legacy
+use iso_c_binding
 implicit none
   interface
 

tests/regression/simple/bindgen_regression_simple.f90

@@ -1,5 +1,6 @@
 ! This file is generated!
 module bindgen_regression_simple
+use iso_c_binding
 implicit none
   interface
 

tests/unit_tests/test_export.cpp

@@ -120,6 +120,7 @@ void test_cpp_bindgen_and_wrapper_compatible_type_b(bindgen_fortran_array_descri
 
     const char expected_fortran_interface[] = R"?(! This file is generated!
 module my_module
+use iso_c_binding
 implicit none
   interface
 

tests/unit_tests/test_generator.cpp

@@ -54,6 +54,7 @@ void qux(int, bindgen_fortran_array_descriptor*);
 
         const char expected_fortran_interface[] = R"?(! This file is generated!
 module my_module
+use iso_c_binding
 implicit none
   interface