A version block might need to be omitted for reasons beyond just
"future". Support all the same tags we do at symbol scope.
Test: `make ndk` with libc/libm migration patches.
Change-Id: I21f54c67079dae10fee1e5e08bcd01f8810e7a67
Symbols that have been added to a library but should not be exposed
in any of the current NDK API levels should be tagged with "future".
These will be suppressed from the NDK libraries.
Once all this is in better shape we'll have `sdk: "current"`. Symbols
tagged with "future" will be available for that.
Note that this tag can be applied directly to a version. Aside from
being more ergonomic than tagging an entire section, this also solved
the problem of gen_stub_libs.py emitting an empty global section
(which is not valid syntax) in the case where every symbol is
"future". Tag the version instead and it will be omitted.
Test: `make ndk` with libc/libm migration patches.
Change-Id: I41f6e4939c406f695ab5725f360ec6554ad8ab31
The list of migrated libraries is currently empty. Libraries will be
migrated as follow up patches.
Test: Migrated libc to this system and everything still builds.
build.ninja shows libraries being built and used and headers are
collected for the sysroot.
Bug: http://b/27533932
Change-Id: Iaba00543c1390f432befe0eed768ed3fbb8a9b96
