* build.zig: repair the ability to link against llvm, clang, and lld
* move the zig cc arg parsing logic to stage2
- the preprocessor flag is still TODO
- the clang arg iterator code is improved to use slices instead of
raw pointers because it no longer has to deal with an extern
struct.
* clean up error printing with a `fatal` function and use log API
for messages rather than std.debug.print
* add support for more CLI options to stage2 & update usage text
- hooking up most of these new options is TODO
* clean up the way libc and libc++ are detected via command line
options. target information is used to determine if any of the libc
candidate names are chosen.
* add native library directory detection
* implement the ability to invoke clang from stage2
* introduce a build_options.have_llvm so we can comptime branch
on whether LLVM is linked in or not.
In an MSVC context, `-MT` means
"Use static run-time"
and it is a flag with no parameter.
On POSIX it means
"Specify name of main file output in depfile"
and it is "joined or separate".
The former was interfering with the latter. Now, the MT flag is required
to be specified with a `/` to disambiguate: `/MT`.
* The generated options data file is sorted now in a way that
makes sure longer prefixes are first. This prevents collisions
with some parameters.
* Add support for `-fPIC`, `-fno-PIC`, `-nostdlib`, `-shared`,
`-rdynamic`, `-Wl,-soname`, `-Wl,-rpath`
* Better support for `-o`.
* Disable generating h files
* Shared library support.
* Better positional argument support.
