[cmake] force no prefix/postfix for debug libs

we explicitly prevent any submodules from setting CMAKE_DEBUG_POSTFIX by
setting this *and forcing this* in the prolog, so that we don't end up
with a situation where a module infects the build environment with this
CMAKE variable. Sticky CMake Variables suck.

Author: tgfrerer

CMakeLists.txt.island_prolog.in

@@ -24,6 +24,8 @@ endif()
 set ( STATIC_LIBRARIES "" CACHE INTERNAL "static_libraries" )
 set ( DEPENDENCY_DEPTH 0 CACHE INTERNAL "current depth in dependency hierarchy" )
 
+set(CMAKE_DEBUG_POSTFIX "" CACHE STRING "Suffix for debug builds" FORCE)
+
 set ( PLUGIN_LIBS_DEPENDENCIES "" CACHE INTERNAL "plugins_libs_dependencies" )
 set ( PLUGIN_LINK_DIRS "")