Modifications to compile with llvm compilers (aocc-flang)

[krahmouasy]

This patch aim to fix the issues discussed in email last week which are present when compiling with llvm/aocc-flang.

• src/dmc/dumper.f90 : Fix the call to mpi_send which were previously mpi_isend but weren't modified in this part of the code.
• src/vmc/ewald.f90 : Modify derfc into erfc. derfc isn't supported by llvm and is also described by gnu as an archaic form. Both are equivalent with erfc adapting to any KIND. https://gcc.gnu.org/onlinedocs/gcc-3.4.6/g77/ErFC-Intrinsic.html#ErFC-Intrinsic
• src/vmc/optwf_olbfgs_more.f90 : Change the name of parameters_old to parms_old in accordance with naming of parms_lbfgs . Previous name isn't properly parsed in some cases (most likely due to "parameters") and raise a compilation error. Please note that 4e10088fe02cde44b8f14cf7cae43b1c48562954 appears to have fixed this one but this modification would make it more robust anyway.

Previously reported modifications to src/parser/fdf.F90 appears to have already been fixed. Another pull request should follow next week to implement modifications to CMakeLists.txt and CMakeModules/FindSIMD.cmake

[neelravi]

Thank you very much @krahmouasy!