Dump out the largest symbols in flash and in RAM. (qmk#17397)

builddefs/build_keyboard.mk

@@ -472,6 +472,19 @@ check-size: build
 check-md5: build
 objs-size: build
 
+ifeq ($(strip $(TOP_SYMBOLS)),yes)
+all: top-symbols
+check-size: top-symbols
+top-symbols: build
+	echo "###########################################"
+	echo "# Highest flash usage:"
+	$(NM) -Crtd --size-sort $(BUILD_DIR)/$(TARGET).elf | grep -i ' [t] ' | head -n10 | sed -e 's#^0000000#       #g' -e 's#^000000#      #g' -e 's#^00000#     #g' -e 's#^0000#    #g' -e 's#^000#   #g' -e 's#^00#  #g' -e 's#^0# #g'
+	echo "###########################################"
+	echo "# Highest RAM usage:"
+	$(NM) -Crtd --size-sort $(BUILD_DIR)/$(TARGET).elf | grep -i ' [dbv] ' | head -n10 | sed -e 's#^0000000#       #g' -e 's#^000000#      #g' -e 's#^00000#     #g' -e 's#^0000#    #g' -e 's#^000#   #g' -e 's#^00#  #g' -e 's#^0# #g'
+	echo "###########################################"
+endif
+
 include $(BUILDDEFS_PATH)/show_options.mk
 include $(BUILDDEFS_PATH)/common_rules.mk