FOLD_CHK_INTEGRAL rejects pointer types
Should emit errors for certain operations on pointers
Error out on certain unary arithmetic with pointer types
Merge branch 'fix/pointer-operators'
Removed warn_mode enum - warnings are now part of a struct
Starting s/warn_at/cc1_&/g
cc1_warn_at() replaces most warn_at() calls
All warnings have an option - also renamed some variables
Removed/merged TODO warnings
Implement int-pointer conversion warning
Warn if a -Wwarning isn't recognised
Implement -Wall, -Wextra and -Weverything
Optionally show the -Woption when a warning is emitted
Warning flag changes in tests
Implicit casts from 0 -> ptr and ptr -> bool are fine
Merge branch 'refactor/warnings'

Conflicts:
	src/cc1/Makefile.dep
	src/cc1/fold_sym.c
Upped the maximum number of nested includes allowed
Add -fsystem-cpp to use the system preprocessor