Makefile: Add target 'install-revive' to build revive with the
installation path specified by variable REVIVE_INSTALL_DIR.
Add utils directory with scripts for building revive in a container.
Add utils/build-revive.sh taking option argument '-o <install-dir>' to
build revive with the specified install directory.
Add utils/revive-builder-debian.dockerfile to make a docker container
for building revive in a Debian environment.
Add option --recursive-process-input <filename> for use with
--recursive-process to specify the name of a file to use instead of
reading from stdin.
If --debug-output-dir is set, dump the file passed to the recursive
invocation of the compiler as a JSON file suitable for use with
--recursive-process-input.
These changes are intended to support debugging the compiler and are
only available with DEBUG builds.
Adjust the llvm build script to put the llvm and compiler-rt build
directories outside the llvm-project source directory. A new build
directory 'build' at the toplevel of the revive directory is used
instead. LLVM is built into 'build/llvm' and compiler-rt into
'build/compiler-rt'.
Adjust .gitignore to ignore the contents of the build directory.
This is intended to keep the build artifacts separate from the upstream
sources and any changes made as part of the revive work.
wpt967