gawk: Enable native building

Also update the ASSUME_PROVIDED in bitbake.conf to contain gawk-native
as the dependency is passed in via HOSTTOOLS for native builds.

This allows for recipes to depend on gawk-native, and have the
dependency met if not already provided by the host tools.

(From OE-Core rev: cbc396dd10488990c98bb6fd94c7d10a736d57c1)

Signed-off-by: Nathan Rossi <nathan@nathanrossi.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/conf/bitbake.conf

@@ -176,6 +176,7 @@ ASSUME_PROVIDED = "\
     chrpath-native \
     file-native \
     findutils-native \
+    gawk-native \
     git-native \
     grep-native \
     diffstat-native \

meta/recipes-extended/gawk/gawk_4.1.4.bb

@@ -46,4 +46,4 @@ do_install_ptest() {
 	done
 }
 
-BBCLASSEXTEND = "nativesdk"
+BBCLASSEXTEND = "native nativesdk"