toolchain: introduce BR2_TOOLCHAIN_HAS_GCC_BUG_101915

lmbench package fails to build for the Microblaze architecture with
optimization enabled with gcc = 11.1.0:
http://autobuild.buildroot.net/results/ae1/ae1e4d61ed367c6cb64442c60d98882cc7985346/

It's been reported upstream:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101915

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

toolchain/Config.in

@@ -190,6 +190,13 @@ config BR2_TOOLCHAIN_HAS_GCC_BUG_101952
 	bool
 	default y if BR2_sh4
 
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101915
+# ICE: in extract_insn, at recog.c:2294 on microblaze.
+# This bug still exists in gcc = 11.1.0
+config BR2_TOOLCHAIN_HAS_GCC_BUG_101915
+	bool
+	default y if BR2_microblaze
+
 config BR2_TOOLCHAIN_HAS_NATIVE_RPC
 	bool