pango: Fix module exports

[dmik]

Pango language modules export a bunch of symbols starting with script_engine_. The OS/2 build does this as well but the symbols start with underscores (of course) so that the module loader (and various tests) can't find them afterwards. Unfortunately, there is no easy way to solve this as some thinking needs to be done.

[dmik]

There are basically two ways to solve the problem:

1. Export the symbols from the DLL with non-underscored aliases. Looks good but a) libtool doesn't let to do it even with -export-symbols MY.DEF because it applies special processing to this DEF file on OS/2 and still prefixes all symbols with underscores; b) I can't recall if the import library will be able to correctly resolve such symbols (as from the C point of view they should have underscores).

2. Use _System calling convention on OS/2 for script_engine_ symbols. Doesn't need a special DEF file and a libtool fix, the import library will surely work but this requires strictly platform-dependent bits in the source code which is also not very good.

[dmik]

Until this issue is solved, our RPMs will not provide these language modules as they can't be currently loaded.

[Silvan Scherrer]

We might need that later on, as some of those languages are used.