Allow to build CharacterMap for the test_app_server.

- I needed to test missing glyphs, and none of the available test apps
  allowed to do so.

src/apps/charactermap/Jamfile

@@ -1,6 +1,7 @@
 SubDir HAIKU_TOP src apps charactermap ;
 
 SetSubDirSupportedPlatformsBeOSCompatible ;
+AddSubDirSupportedPlatforms libbe_test ;
 
 UsePrivateHeaders shared system ;
 
@@ -23,3 +24,8 @@ DoCatalogs CharacterMap :
 	CharacterWindow.cpp
 	UnicodeBlocks.cpp
 ;
+
+if $(TARGET_PLATFORM) = libbe_test {
+	HaikuInstall install-test-apps : $(HAIKU_APP_TEST_DIR) : CharacterMap
+		: tests!apps ;
+}