Bump buidlroot version to 2018.02.6

bsp/buildroot/package/gcc/6.4.0/870-xtensa-fix-PR-target-82181.patch

@@ -0,0 +1,31 @@
+From 3bc2ee6886f1619bc6a2257a0775142526b1a57a Mon Sep 17 00:00:00 2001
+From: jcmvbkbc <jcmvbkbc@138bc75d-0d04-0410-961f-82ee72b054a4>
+Date: Mon, 11 Sep 2017 21:53:38 +0000
+Subject: [PATCH] xtensa: fix PR target/82181
+
+2017-09-11  Max Filippov  <jcmvbkbc@gmail.com>
+gcc/
+	Backport from mainline
+	* config/xtensa/xtensa.c (xtensa_mem_offset): Check that both
+	words of DImode object are reachable by xtensa_uimm8x4 access.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+ gcc/config/xtensa/xtensa.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/gcc/config/xtensa/xtensa.c b/gcc/config/xtensa/xtensa.c
+index 2bdf5ccef979..92fdeb08046d 100644
+--- a/gcc/config/xtensa/xtensa.c
++++ b/gcc/config/xtensa/xtensa.c
+@@ -601,6 +601,7 @@ xtensa_mem_offset (unsigned v, machine_mode mode)
+     case HImode:
+       return xtensa_uimm8x2 (v);
+ 
++    case DImode:
+     case DFmode:
+       return (xtensa_uimm8x4 (v) && xtensa_uimm8x4 (v + 4));
+ 
+-- 
+2.1.4
+