Merge pull request ARMmbed#10615 from andrewc-arm/patch_cc1

This allows CPP application to use the functions from cc.h.

Author: 0xc0170

features/lwipstack/lwip-sys/arch/cc.h

@@ -40,6 +40,9 @@
 #include "mbedtls/md5.h"
 #endif
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /* ARM/LPC17xx is little endian only */
 #if !defined(BYTE_ORDER) || (BYTE_ORDER != LITTLE_ENDIAN && BYTE_ORDER != BIG_ENDIAN)
@@ -180,4 +183,8 @@ SET_MEMP_SECTION(memp_memory_PPP_PCB_base);
 #endif
 #endif
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __CC_H__ */