I.e., llvm/CodeGen/CommandFlags.h which in turn includes
llvm/MC/MCTargetOptionsCommandFlags.h.
This gets rid of a few duplicates on our side and includes about 35
(depending on LLVM version) new command-line options. LLVM provides a
helper function to set up the TargetOptions according to (most of) these
options.
Newer LLVM versions may add new options and we'll automatically inherit
them, including setting up the TargetOptions accordingly.
I did my best (TM) to remove a few unused/undesirable options and hide all
remaining new ones except for `-fp-contract`. The lists will need to be
tweaked from time to time.
* Remove default label in switch which covers all enumeration values.
This fixes the warning "default label in switch which covers all enumeration values". We will already get a warning when _not_ all enumeration values are covered.
This is the last warning left on OSX/Clang, so with this change, we can build with -Werror.
* Fix warning: enumeral and non-enumeral type in conditional expression
* Fix warning: '%d' directive output may be truncated writing between 1 and 10 bytes into a region of size 5
* "fallthrough" is recognized by the compiler warning system
