Fix various issues with PGO+LTO makefile (#55581)
This fixes various issues with the PGO+LTO makefile
- `USECCACHE` doesn't work throwing an error at
https://github.com/JuliaLang/julia/blob/eb5587dac02d1f6edf486a71b95149139cc5d9f7/Make.inc#L734
This is because setting `CC` and `CCX` by passing them as arguments to
`make` prevents `Make.inc` from prepending these variables with `ccache`
as `Make.inc` doesn't use override. To workaround this I instead set
`USECLANG` and add the toolchain to the `PATH`.
- To deal with similar issues for the other make flags, I pass them as
environment variables which can be edited in `Make.inc`.
- I add a way to build in one go by creating the `all` target, now you
can just run `make` and a PGO+LTO build that profiles Julia's build will
be generated.
- I workaround `PROFRAW_FILES` not being reevaluated after `stage1`
builds, this caused the generation of `PROFILE_FILE` to run an outdated
command if `stage1` was built and affected the profraw files. This is
important when building in one go.
- I add a way to run rules like `binary-dist` which are not defined in
this makefile with the correct toolchain which for example prevents
`make binary-dist` from unnecessarily rebuilding `sys.ji`.
- Include `-Wl,--undefined-version` till
https://github.com/JuliaLang/julia/issues/54533 gets fixed.
These changes need to be copied to the PGO+LTO+BOLT makefile and some to
the BOLT makefile in a later pr.
---------
Co-authored-by: Zentrik <Zentrik@users.noreply.github.com>
