I was using the project file CodeBlocks_wx29.cbp to compile using wxWidgets 2.9.3. I noticed that the wxscintilla source code is being compiled to create a static library, libwxscintilla_cb.a. I don’t know if you are aware of it, but wxscintilla is included in the 2.9 release. Compiling the wxWidgets DLL creates a libwxscintilla.a you can link against. It is included by default with the option USE_STC=1 (in config.gcc).
Also MinGW release 4.6.2 will compile wxWidgets 2.9.3 WITHOUT changes to config.gcc. It also compiles in a reasonable time, about 40 minutes on my machine. It will NOT compile 2.8.12 without the config.gcc changes however. WxWidgets could have made changes to 2.9.3, like removing some inline dll exports.