Fix toolchain gcc compilation with newer host gcc

An inline attribute mismatch in the gcc-4.9.2 source causes its
compilation to fail on modern gcc versions (verified with gcc 6.3.1,
but probably since gcc 5)
The patch is courtesy of the gcc-patches mailing list:
https://gcc.gnu.org/ml/gcc-patches/2015-08/msg00375.html

Fixes #2341

repos/ports/ports/gcc.hash

@@ -1 +1 @@
-fe976d168f9937cac0ffaa7ec4999d385d076fe2
+6f36711bdcf68dc66357563c8429cd29d8e92003

tool/patches/gcc-4.9.2/gnu_inline_mismatch.patch

@@ -0,0 +1,33 @@
+Required for building with newer gcc
+
+See https://gcc.gnu.org/ml/gcc-patches/2015-08/msg00375.html
+
+--
+diff --git a/gcc/cp/cfns.gperf b/gcc/cp/cfns.gperf
+index 68acd3d..953262f 100644
+--- a/gcc/cp/cfns.gperf
++++ b/gcc/cp/cfns.gperf
+@@ -22,6 +22,9 @@ __inline
+ static unsigned int hash (const char *, unsigned int);
+ #ifdef __GNUC__
+ __inline
++#ifdef __GNUC_STDC_INLINE__
++__attribute__ ((__gnu_inline__))
++#endif
+ #endif
+ const char * libc_name_p (const char *, unsigned int);
+ %}
+diff --git a/gcc/cp/cfns.h b/gcc/cp/cfns.h
+index 1c6665d..6d00c0e 100644
+--- a/gcc/cp/cfns.h
++++ b/gcc/cp/cfns.h
+@@ -53,6 +53,9 @@ __inline
+ static unsigned int hash (const char *, unsigned int);
+ #ifdef __GNUC__
+ __inline
++#ifdef __GNUC_STDC_INLINE__
++__attribute__ ((__gnu_inline__))
++#endif
+ #endif
+ const char * libc_name_p (const char *, unsigned int);
+ /* maximum key range = 391, duplicates = 0 */

tool/patches/gcc-4.9.2/series

@@ -10,3 +10,4 @@ libsupcxx_demangle.patch
 libgcc_s.patch
 go_libbacktrace.patch
 target_libbacktrace.patch
+gnu_inline_mismatch.patch