ANDROID: Add CONFIG_LLD_VERSION

CONFIG_LLD_VERSION was originally added in commit d5750cd3c548 ("kbuild:
Disable CONFIG_LD_ORPHAN_WARN for ld.lld 10.0.1"), which is not
applicable to 4.19. Additionally, lld-version.sh was eliminated and
combined into ld-version.sh in commit 02aff8592204 ("kbuild: check the
minimum linker version in Kconfig") and there was a follow up fix in
commit 1f09af062556 ("kbuild: Fix ld-version.sh script if LLD was built
with LLD_VENDOR"), which is a little large to take into
android-4.19-stable for the sake of fixing an LTO issue.

Add scripts/lld-version.sh but based on the upstream version of
ld-version.sh so that we benefit from the fixes but do not have to
backport a ton of patches just to get access to CONFIG_LLD_VERSION.

Change-Id: I686ce6cc5f503540d8336b914f0fe978951c469b
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

init/Kconfig

@@ -26,6 +26,10 @@ config CLANG_VERSION
 	int
 	default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
 
+config LLD_VERSION
+	int
+	default $(shell,$(srctree)/scripts/lld-version.sh $(LD))
+
 config CC_HAS_ASM_GOTO
 	def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
 

scripts/lld-version.sh

@@ -0,0 +1,36 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# Print ld.lld's version in a 5 or 6-digit form.
+
+set -e
+
+# Convert the version string x.y.z to a canonical 5 or 6-digit form.
+get_canonical_version()
+{
+	IFS=.
+	set -- $1
+
+	# If the 2nd or 3rd field is missing, fill it with a zero.
+	echo $((10000 * $1 + 100 * ${2:-0} + ${3:-0}))
+}
+
+orig_args="$@"
+
+# Get the first line of the --version output.
+IFS='
+'
+set -- $(LC_ALL=C "$@" --version)
+
+# Split the line on spaces.
+IFS=' '
+set -- $1
+
+while [ $# -gt 1 -a "$1" != "LLD" ]; do
+	shift
+done
+if [ "$1" = LLD ]; then
+	echo $(get_canonical_version ${2%-*})
+else
+	echo 0
+fi