Handle primitive types when expanding "resolved_type" in typemaps

Although the default typemaps only use "resolved_type" for non-simple types,
the generic SWIGTYPE typemap can also be applied explicitly to other types as
"apply_strings" and "char_binary" unit tests do.

In this case just use the original type unchanged if we can, this is enough to
make these tests pass.

Examples/test-suite/c/Makefile.in

@@ -47,14 +47,12 @@ FAILING_C_TESTS := \
 FAILING_CPP_TESTS := \
     abstract_typedef2 \
     apply_signed_char \
-    apply_strings \
     array_member \
     array_typedef_memberin \
     arrayref \
     arrays_dimensionless \
     arrays_global \
     arrays_global_twodim \
-    char_binary \
     char_strings \
     class_ignore \
     class_scope_weird \