Address review comments
Integer output data editing (I,B,O,Z)
Full integer output formatting
Stub out some work in progress
Progress on E output data editing
E, D, EN, and ES output editing done
Fw.d output editing
Real G output editing
G output editing for reals
Make environment a distinct module
CHARACTER and LOGICAL output editing
Minimal decimal representations for E0, F0, G0 editing
Move real output editing code into its own file
Fix/dodge some GCC build problems
Prep work for external I/O statement state
External HELLO, WORLD
Fix build problem with GCC
Add virtual destructors where needed
Add new test
Original-commit: flang-compiler/f18@c3f1774f8e
Reviewed-on: https://github.com/flang-compiler/f18/pull/950
Diana Picus