Now, if the same file exists in the generated tree and the source tree,
it symlinks in the generated file instead of failing outright.
Drive-by fix: print errors for all conflicts instead of bailing out on
the first one.
Test: Presubmits (including the two new tests)
Change-Id: Ifb5b3fc89b5454d231966bfa4e61c22cd69834f3
It's under out/soong/workspace and is a symlink forest that merges BUILD
files generated by bp2build and the source tree.
bazel-* symlinks and $OUTDIR are currently ignored.
Test: Presubmits.
Change-Id: If14df23bd0f6a6f2d7d1140f95213f2aee66d652