Use -fvisibility=hidden for shared libraries

Applying: aix: No need to use mkldexport when we want to export all symbols
Using index info to reconstruct a base tree...
M	src/Makefile.shlib
M	src/makefiles/Makefile.aix
Falling back to patching base and 3-way merge...
Auto-merging src/makefiles/Makefile.aix
Auto-merging src/Makefile.shlib
CONFLICT (content): Merge conflict in src/Makefile.shlib
Patch failed at 0001 aix: No need to use mkldexport when we want to export all symbols

error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config advice.mergeConflict false"