Makefile: Replace old suffix rules with pattern rules

As mentioned here [1], suffix rules are obsolete and have been
superseeded with pattern rules.  People (myself included, before writing
this patch) are more likely to know what pattern rules are than suffix
rules.

AFAIK, .SUFFIXES targets are only used for those rules, and can be
removed as well.

New in v2:

  - Replace rule in gdbserver/Makefile.in as well.

[1] https://www.gnu.org/software/make/manual/html_node/Suffix-Rules.html

gdb/ChangeLog:

	* Makefile.in (.c.o): Replace rule with ...
	(%.o: %.c): ... this one.
	(.po.gmo): Replace rule with ...
	(%.gmo: %.po): ... this one.
	(.po.pox): Replace rule with ...
	(%.pox: %.po): ... this one.
	(.y.c): Replace rule with ...
	(%.c: %.y): ... this one.
	(.l.c): Replace rule with ...
	(%.c: %.l): ... this one.
	(.SUFFIXES): Remove all instances.

gdb/gdbserver/ChangeLog:

	* Makefile.in (.c.o): Replace rule with ...
	(%.o: %.c): ... this one.

gdb/ChangeLog

@@ -1,3 +1,17 @@
+2016-11-17  Simon Marchi  <simon.marchi@polymtl.ca>
+
+	* Makefile.in (.c.o): Replace rule with ...
+	(%.o: %.c): ... this one.
+	(.po.gmo): Replace rule with ...
+	(%.gmo: %.po): ... this one.
+	(.po.pox): Replace rule with ...
+	(%.pox: %.po): ... this one.
+	(.y.c): Replace rule with ...
+	(%.c: %.y): ... this one.
+	(.l.c): Replace rule with ...
+	(%.c: %.l): ... this one.
+	(.SUFFIXES): Remove all instances.
+
 2016-11-17  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* Makefile.in: Remove @GMAKE_TRUE@ prefixes and removes lines

gdb/Makefile.in

@@ -1122,7 +1122,7 @@ DISTSTUFF = $(YYFILES)
 generated_files = config.h observer.h observer.inc ada-lex.c jit-reader.h \
 	$(GNULIB_H) $(NAT_GENERATED_FILES) gcore
 
-.c.o:
+%.o: %.c
 	$(COMPILE) $<
 	$(POSTCOMPILE)
 
@@ -1801,7 +1801,6 @@ ada-exp.o: ada-exp.c
 # Rules for generating translated message descriptions.  Disabled by
 # autoconf if the tools are not available.
 
-.SUFFIXES: .po .gmo .pox .pot
 .PHONY: all-po install-po uninstall-po clean-po update-po $(PACKAGE).pot
 
 all-po: $(CATALOGS)
@@ -1812,14 +1811,14 @@ update-po: $(CATALOGS:.gmo=.pox)
 
 # N.B. We do not attempt to copy these into $(srcdir).  The snapshot
 # script does that.
-.po.gmo:
+%.gmo: %.po
 	-test -d po || mkdir po
 	$(GMSGFMT) --statistics -o $@ $<
 
 # The new .po has to be gone over by hand, so we deposit it into
 # build/po with a different extension.  If build/po/$(PACKAGE).pot
 # exists, use it (it was just created), else use the one in srcdir.
-.po.pox:
+%.pox: %.po
 	-test -d po || mkdir po
 	$(MSGMERGE) $< `if test -f po/$(PACKAGE).pot; \
 			then echo po/$(PACKAGE).pot; \
@@ -1880,8 +1879,7 @@ po/$(PACKAGE).pot: force
 # Strictly speaking c-exp.c should therefore depend on
 # Makefile.in, but that was a pretty big annoyance.
 
-.SUFFIXES: .y .l
+%.c: %.y
-.y.c:
 	rm -f $@ $@.tmp
 	$(SHELL) $(YLWRAP) $< y.tab.c $@ -- $(YACC) $(YFLAGS) && mv $@ $@.tmp \
 		|| (rm -f $@; false)
@@ -1897,7 +1895,7 @@ po/$(PACKAGE).pot: force
 	     -e 's/YY_NULL/YY_NULLPTR/g' \
 	  < $@.tmp > $@
 	rm -f $@.tmp
-.l.c:
+%.c: %.l
 	if [ "$(FLEX)" ] && $(FLEX) --version >/dev/null 2>&1; then \
 	    $(FLEX) -o$@ $< && \
 	    rm -f $@.new && \

gdb/gdbserver/ChangeLog

@@ -1,3 +1,8 @@
+2016-11-17  Simon Marchi  <simon.marchi@polymtl.ca>
+
+	* Makefile.in (.c.o): Replace rule with ...
+	(%.o: %.c): ... this one.
+
 2016-11-17  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* Makefile.in: Remove @GMAKE_TRUE@ prefixes and removes lines

gdb/gdbserver/Makefile.in

@@ -256,7 +256,7 @@ FLAGS_TO_PASS = \
 # All generated files which can be included by another file.
 generated_files = config.h $(GNULIB_H)
 
-.c.o:
+%.o: %.c
 	$(COMPILE) $<
 	$(POSTCOMPILE)