Merge "build: fix grouped targets on Make <= 4.2" into integration
diff --git a/lib/romlib/Makefile b/lib/romlib/Makefile
index 3d2b850..4cac75b 100644
--- a/lib/romlib/Makefile
+++ b/lib/romlib/Makefile
@@ -73,7 +73,7 @@
 	$(s)echo "  PRE     $@"
 	$(q)$(ROMLIB_GEN) pre --output $@ --deps $(BUILD_DIR)/jmptbl.d $<
 
-$(WRAPPER_SOURCES) &: $(BUILD_DIR)/jmptbl.i | $$(@D)/
+$(WRAPPER_SOURCES) $&: $(BUILD_DIR)/jmptbl.i | $$(@D)/
 	$(s)echo "  WRP     $<"
 	$(q)$(ROMLIB_GEN) genwrappers --bti=$(ENABLE_BTI) -b $(WRAPPER_DIR) $<
 
diff --git a/make_helpers/utilities.mk b/make_helpers/utilities.mk
index efa0ab9..fcccd24 100644
--- a/make_helpers/utilities.mk
+++ b/make_helpers/utilities.mk
@@ -22,6 +22,13 @@
 escape-shell = '$(subst ','\'',$(1))'
 
 #
+# The grouped-target symbol. Grouped targets are not supported on versions of
+# GNU Make <= 4.2, which was most recently packaged with Ubuntu 20.04.
+#
+
+& := $(if $(filter grouped-target,$(.FEATURES)),&)
+
+#
 # Upper-case a string value.
 #
 # Parameters: