[libbacktrace] Fix and simplify xcoff_%.c pattern rule

When generating xcoff_%.c, the last command is a sed command.  In case of a
sed failure, this will leave an incomplete file, which will appear as up to
date to make, so consequently it will not be regenerated.  Fix this by
sedding into a temporary file instead.

Also, use $< to access the prerequisite xcoff.c, instead of spelling out the
file name once more.

2019-01-28  Tom de Vries  <tdevries@suse.de>

	* Makefile.am (xcoff_%.c): Generate sed result into temporary file.
	Use $< to access prerequisite.
	* Makefile.in: Regenerate.

From-SVN: r268344

libbacktrace/ChangeLog

+2019-01-28  Tom de Vries  <tdevries@suse.de>
+
+	* Makefile.am (xcoff_%.c): Generate sed result into temporary file.
+	Use $< to access prerequisite.
+	* Makefile.in: Regenerate.
+
 2019-01-25  Nathan Sidwell  <nathan@acm.org>
 
 	* elf.c (elf_add): Pass "" filename to recursive call with

libbacktrace/Makefile.am

@@ -108,8 +108,9 @@ xcoff_%.c: xcoff.c
 	REPLACE='#undef BACKTRACE_XCOFF_SIZE\
 	#define BACKTRACE_XCOFF_SIZE'; \
 	$(SED) "s/^$$SEARCH\$$/$$REPLACE $*/" \
-		$(srcdir)/xcoff.c \
-		> $@
+		$< \
+		> $@.tmp
+	mv $@.tmp $@
 
 test_elf_SOURCES = test_format.c testlib.c
 test_elf_LDADD = libbacktrace_noformat.la elf.lo

libbacktrace/Makefile.in

@@ -1754,8 +1754,9 @@ uninstall-am:
 @NATIVE_TRUE@	REPLACE='#undef BACKTRACE_XCOFF_SIZE\
 @NATIVE_TRUE@	#define BACKTRACE_XCOFF_SIZE'; \
 @NATIVE_TRUE@	$(SED) "s/^$$SEARCH\$$/$$REPLACE $*/" \
-@NATIVE_TRUE@		$(srcdir)/xcoff.c \
-@NATIVE_TRUE@		> $@
+@NATIVE_TRUE@		$< \
+@NATIVE_TRUE@		> $@.tmp
+@NATIVE_TRUE@	mv $@.tmp $@
 
 @NATIVE_TRUE@instrumented_alloc.lo: alloc.c