implemented low-level replace_all function#436

Merged

awvwgk merged 9 commits intofortran-lang:masterfrom

aman-godara:replace_all

Jul 4, 2021

Commits on Jun 20, 2021

implemented replace_all function, added some test_cases for replace_all
aman-godara
committed

Commits on Jun 24, 2021

replaced replace_all_char_char_char with replace_all
aman-godara
committed

Commits on Jun 28, 2021

optimised replace_all by using intrinsic character slicing
aman-godara
committed

Commits on Jul 3, 2021

Small style edit for consistency
milancurcic
committed