The PROJ_SRC_DIR != PROJ_OBJ_DIR path was missing the directory
creation logic that was in the path for non-generated headers.
PR11903.
(The oversight was copied and pasted from LLVM's Makefile.rules,
where it apparently existed since time immemorial til it was
corrected in r127325.)
llvm-svn: 149551
Specify that these files should be installed to the optional internal
install location as specified by configure's --with-internal-prefix.
If that option is not used, they'll be installed to the default prefix
as before.
llvm-svn: 145235
Dylan Noblesmith