Author: misaka00251 <liuxin@iscas.ac.cn>
Date:   Wed Sep 21 11:15:51 2022 +0800

	Fix support for RISC-V.

diff --git a/c++/src/build-system/config.guess b/c++/src/build-system/config.guess
index f475ceb..57481db 100755
--- a/c++/src/build-system/config.guess
+++ b/c++/src/build-system/config.guess
@@ -979,6 +979,9 @@ EOF
     ppc:Linux:*:*)
 	echo powerpc-unknown-linux-gnu
 	exit ;;
+	riscv32:Linux:*:* | riscv32be:Linux:*:* | riscv64:Linux:*:* | riscv64be:Linux:*:*)
+	echo ${UNAME_MACHINE}-unknown-linux-gnu
+	exit ;;
     s390:Linux:*:* | s390x:Linux:*:*)
 	echo ${UNAME_MACHINE}-ibm-linux
 	exit ;;