1. Check for Perl and only build llvm-config if its available.
2. Add some virtual components
3. Don't depend on "standard" location for Perl, but configured location
4. Document the tool with a POD file.
This version is now ready for testing by users.
llvm-svn: 27005
* "dist" target now builds tar.gz, tar.bz2, and zip files suitable for
distribution. "dist" can only be run from $(BUILD_OBJ_ROOT) and implies
a "check".
* made the preconditions not do a recursive make and ensured that they are
executed sequentially.
* made the messages output by the makefile be prefixed with "llvm" and the
make level (e.g. llvm[1]: ) in the same way that make does so that the
messages are uniform and more readable.
* Fixed the tags target so that tags depends on TAGS which contains the
rules to build a file named TAGS
* Implemented the EXTRA_DIST feature in a few directories to make sure it
works.
llvm-svn: 17210
