Bump the i386 architecture GNU triplet to i586-linux-gnu

This matches the change in gcc. Somewhat reluctantly, as i386 wants to
be its unique snowflake and use a GNU triplet not matching its baseline.
This will cause problems when cross-building and using unmatched
combinations of dpkg-dev and gcc.

Closes: #751363

cputable

@@ -14,7 +14,7 @@
 # Column 5 is the endianness (byte ordering in numbers)
 #
 # <Debian name>	<GNU name>	<config.guess regex>	<Bits>	<Endianness>
-i386		i486		(i[3456]86|pentium)	32	little
+i386		i586		(i[3456]86|pentium)	32	little
 ia64		ia64		ia64			64	little
 alpha		alpha		alpha.*			64	little
 amd64		x86_64		x86_64			64	little

debian/changelog

@@ -65,6 +65,11 @@ dpkg (1.17.11) UNRELEASED; urgency=low
   * Print the correct removed binary filename when building a source package
     with dpkg-source --include-removal. Closes: #755166
   * Add powerpcel support to cputable. Thanks to Jae Junh <jaejunh@embian.com>.
+  * Bump the i386 architecture GNU triplet to i586-linux-gnu to match the
+    change in gcc. Somewhat reluctantly, as i386 wants to be its unique
+    snowflake and use a GNU triplet not matching its baseline. This will
+    cause problems when cross-building and using unmatched combinations of
+    dpkg-dev and gcc. Closes: #751363
 
   [ Updated programs translations ]
   * Danish (Joe Dalton). Closes: #754127

debian/rules

@@ -80,7 +80,7 @@ install: check
 
 ifeq (yes,$(shell dpkg-vendor --derives-from Ubuntu && echo yes))
 	# Ubuntu's «i386» architecture is built for i686 (the Debian default
-	# is i486).
+	# is i586).
 	sed -ri 's/^(i386[[:space:]]+)[^[:space:]]+/\1i686/' \
 	        $(CURDIR)/debian/tmp/usr/share/dpkg/cputable
 endif