Addressing the limit of the length for a Fortran subroutine name

[zhucaoxiang]

@jameskermode I got another issue. Sorry for bothering you again.

When wrapping a variable with a long name, it is easy to get the error of subroutine name is too long. For Fortran90 or Fortran 2008, the limit of a subroutine name is something like 60. I guess we can replace the auto-generated name with some other names (when the length exceeds 60) to make it more generalized.

f90wrap_regcoil_variables.f90:2463:75:

 2463 | subroutine f90wrap_regcoil_variables__array__this_Laplace_Beltrami2_times_N(dummy_this, nd, dtype, dshape, dloc)
      |                                                                           1
Error: Name at (1) is too long