clang/gcc: Add build option FREECAD_WARN_ERROR to force to make warnings into errors

src/Mod/PartDesign/App/CMakeLists.txt

@@ -143,6 +143,9 @@ SET(PartDesign_SRCS
 
 add_library(PartDesign SHARED ${PartDesign_SRCS})
 target_link_libraries(PartDesign ${PartDesign_LIBS})
+if (FREECAD_WARN_ERROR)
+    target_compile_warn_error(PartDesign)
+endif()
 
 if(FREECAD_USE_PCH)
     add_definitions(-D_PreComp_)

src/Mod/PartDesign/Gui/CMakeLists.txt

@@ -259,6 +259,9 @@ SET(PartDesignGuiIcon_SVG
 
 add_library(PartDesignGui SHARED ${PartDesignGui_SRCS} ${PartDesignGuiIcon_SVG})
 target_link_libraries(PartDesignGui ${PartDesignGui_LIBS})
+if (FREECAD_WARN_ERROR)
+    target_compile_warn_error(PartDesignGui)
+endif()
 
 SET_BIN_DIR(PartDesignGui PartDesignGui /Mod/PartDesign)
 SET_PYTHON_PREFIX_SUFFIX(PartDesignGui)