[Bug fortran/122816] Missed simplification of concatenation of constant strings

[anlauf at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122816

--- Comment #1 from anlauf at gcc dot gnu.org ---
Created attachment 62903
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=62903&action=edit
Reassociation (scalar case)

This does the reassociation (s1 // s2) // s3 -> s1 // (s2 // s3) in the
scalar case.