Add Go toolchain support

This adds the meta-go-toolchain. It enables the generation of a Go
toolchain allowing for cross compiling for target architecture.

(From OE-Core rev: 8e16694b2f4c4038c56226821699d0d21578bdf0)

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/meta/meta-go-toolchain.bb

@@ -0,0 +1,12 @@
+SUMMARY = "Meta package for building a installable Go toolchain"
+LICENSE = "MIT"
+
+inherit populate_sdk
+
+TOOLCHAIN_HOST_TASK_append = " \
+    packagegroup-go-cross-canadian-${MACHINE} \
+"
+
+TOOLCHAIN_TARGET_TASK_append = " \
+    ${@multilib_pkg_extend(d, 'packagegroup-go-sdk-target')} \
+"

meta/recipes-core/packagegroups/packagegroup-go-cross-canadian.bb

@@ -0,0 +1,12 @@
+SUMMARY = "Host SDK package for Go cross canadian toolchain"
+PN = "packagegroup-go-cross-canadian-${MACHINE}"
+
+inherit cross-canadian packagegroup
+
+PACKAGEGROUP_DISABLE_COMPLEMENTARY = "1"
+
+GO = "go-cross-canadian-${TRANSLATED_TARGET_ARCH}"
+
+RDEPENDS_${PN} = " \
+    ${@all_multilib_tune_values(d, 'GO')} \
+"

meta/recipes-core/packagegroups/packagegroup-go-sdk-target.bb

@@ -0,0 +1,8 @@
+SUMMARY = "Target packages for the Go SDK"
+
+inherit packagegroup
+
+RDEPENDS_${PN} = " \
+    go-runtime \
+    go-runtime-dev \
+"