Create subdirectory checks/errors/feature

gcc/rust/ChangeLog:

	* Make-lang.in: Handle source files in checks/errors/feature.
	* checks/errors/rust-feature-gate.cc: Move to...
	* checks/errors/feature/rust-feature-gate.cc: ...here.
	* checks/errors/rust-feature-gate.h: Move to...
	* checks/errors/feature/rust-feature-gate.h: ...here.
	* checks/errors/rust-feature.cc: Move to...
	* checks/errors/feature/rust-feature.cc: ...here.
	* checks/errors/rust-feature.h: Move to...
	* checks/errors/feature/rust-feature.h: ...here.

Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>

Author: powerboat9

gcc/rust/Make-lang.in

@@ -444,6 +444,7 @@ RUST_INCLUDES = -I $(srcdir)/rust \
 	-I $(srcdir)/rust/checks/errors \
 	-I $(srcdir)/rust/checks/errors/privacy \
 	-I $(srcdir)/rust/checks/errors/borrowck \
+	-I $(srcdir)/rust/checks/errors/feature \
 	-I $(srcdir)/rust/util \
         -I $(srcdir)/rust/metadata \
 		-I $(srcdir)/../libgrust
@@ -516,6 +517,11 @@ rust/%.o: rust/checks/errors/%.cc
 	$(COMPILE) $(RUST_CXXFLAGS) $(RUST_INCLUDES) $<
 	$(POSTCOMPILE)
 
+# build feature related files in rust folder
+rust/%.o: rust/checks/errors/feature/%.cc
+	$(COMPILE) $(RUST_CXXFLAGS) $(RUST_INCLUDES) $<
+	$(POSTCOMPILE)
+
 # build privacy pass files in rust folder
 rust/%.o: rust/checks/errors/privacy/%.cc
 	$(COMPILE) $(RUST_CXXFLAGS) $(RUST_INCLUDES) $<