Hide dependency symbol visibility (#1409) (#1416)
Hide dependency symbol visibility (#1409) (#1416)

When creating libOpenColorIO.so, we lacked the linker commands that
hide symbol visibility from the dependent libraries, which is
necessary to prevent OCIO from exporting the symbols from Expat and
the other dependencies that OCIO needs to use internally but is not
trying intentionally to expose via its API.

Failing to do this can result in symbol clashes and all sorts of
subtle errors if OCIO is used in an app that also uses and is linked
against a potentially different version of Expat (or any of the other
deps).

Signed-off-by: Larry Gritz <f0a1ce6f80112d72f7276457fd261d671b827567@larrygritz.com>

Co-authored-by: Larry Gritz <f0a1ce6f80112d72f7276457fd261d671b827567@larrygritz.com>
AcademySoftwareFoundation/OpenColorIO,AcademySoftwareFoundation/OpenColorIO,AcademySoftwareFoundation/OpenColorIO,AcademySoftwareFoundation/OpenColorIO,AcademySoftwareFoundation/OpenColorIO