Below is listed work to be done, hopefully all of it in 2025 for
GCC 16. They are vaguely in priority order, in that addressing more
technical issues may illuminate ways to attack more amorphous ones.

Portability:
    - host/target, for cross-compilation
    - OS portability, BSD, macOS, Solaris
    - 64-bit portability, LE
    - 64-bit portability, BE
    - 2025 goal: Compile & run on primary & secondary GCC 15 platforms
                 https://www.gnu.org/software/gcc/gcc-15/criteria.html

Correctness:
    - LTO ODR, PR 119215 
    - cppcheck
    - valgrind
    - -static produces dynamic

Efficiency:
    - Code size for MOVE 'a' TO FOO(1,1)
    - EC checking

COBOL Features:
    - XML, JSON
    - MF system functions
    - National characters (and Unicode, for IBM)
    - GLOBAL and PERFORM declaratives
    - dialect feature names (to enable and enumerate)

GCC features:
    - make check-nist
    - -Werror, -Wno-<foo>
    - -fEC-ALL, -fno-EC-I-O