...and fix any ensuing errors/warnings, but no further C++'ification.  Not sure
whether any parts of dllentry.c would need to be extern "C", so leaving that one
alone for now.

TODO: Put definition of _CRT_RAND_S into bin/update_pch, so it doesn't get
removed again from sal/inc/pch/precompiled_sal.hxx.  (For the surrounding #ifndef
see 244d22a3 "Work around -Werror,-Wunused-macros
with clang-cl".)

Change-Id: I2ada3717845eb0be0c559465d68e00e3a7720156
Reviewed-on: https://gerrit.libreoffice.org/34860Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Stephan Bergmann <sbergman@redhat.com>