Some whitespace cleanup, avoids Emacs warning

Change-Id: I5b2c5a249c0446d69ac19d11e0d5e038983f0be8
Use the CLANG_CXX_LIBRARY from lo.xcconfig

Change-Id: Id6424157d2a9ba2a4ab987cd8aafd9c7de52f836
Don't redirect output to /dev/null if verbosity is requested

Change-Id: Idccc7cc8e9f81576bb24fec0a49144c0fcc16fd5
Use hidden visibility as in the LO code here, too

Otherwise we get tons of (as such, in our case harmless) warnings from
the linker about mismatches.

Change-Id: I826d9e065bae59cdd213131163b31b2099806dd3