package/gcc: define _REENTRANT for OpenRISC when -pthread is passed

Fixes:
http://autobuild.buildroot.net/results/ceb802eea0fee5812efd717ae4cdbd9673d9507e/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/gcc/9.3.0/0003-gcc-define-_REENTRANT-for-RISC-V-when-pthread-is-pas.patch

@@ -0,0 +1,31 @@
+From 2aefc4ee703ce3ff70ad25915005cacfbaae0c49 Mon Sep 17 00:00:00 2001
+From: Bernd Kuhls <bernd.kuhls@t-online.de>
+Date: Fri, 27 Mar 2020 21:23:53 +0100
+Subject: [PATCH] gcc: define _REENTRANT for OpenRISC when -pthread is passed
+
+The detection of pthread support fails on OpenRISC unless _REENTRANT
+is defined. Added the CPP_SPEC definition to correct this.
+
+Patch sent upstream: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94372
+
+Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
+---
+ gcc/config/or1k/linux.h | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/gcc/config/or1k/linux.h b/gcc/config/or1k/linux.h
+index 4b2f7b6e1fd..b00d23ddfa0 100644
+--- a/gcc/config/or1k/linux.h
++++ b/gcc/config/or1k/linux.h
+@@ -32,6 +32,8 @@
+ #undef MUSL_DYNAMIC_LINKER
+ #define MUSL_DYNAMIC_LINKER  "/lib/ld-musl-or1k.so.1"
+ 
++#define CPP_SPEC "%{pthread:-D_REENTRANT}"
++
+ #undef LINK_SPEC
+ #define LINK_SPEC "%{h*}			\
+    %{static:-Bstatic}				\
+-- 
+2.21.0
+