[PATCH] RISC-V: Add Zbb extension sext testcase.

[Jiawei]

This patch update RISC-V Zba extension 'sext' instructions generation.
Supplemented the instruction generation detection of 'sext.h' and
'sext.b'.

gcc/testsuite/ChangeLog:

        * gcc.target/riscv/zbb-sext.c: New test.

---
 gcc/testsuite/gcc.target/riscv/zbb-sext.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/riscv/zbb-sext.c

diff --git a/gcc/testsuite/gcc.target/riscv/zbb-sext.c 
b/gcc/testsuite/gcc.target/riscv/zbb-sext.c
new file mode 100644
index 00000000000..1ad3e714371
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/zbb-sext.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=rv64gc_zbb -mabi=lp64" } */
+
+#include<stdint.h>
+
+int8_t foo1(uint8_t a) {
+    return a;
+}
+
+int16_t foo2(uint16_t a) {
+    return a;
+}
+
+/* { dg-final { scan-assembler "sext.b" } } */
+/* { dg-final { scan-assembler "sext.h" } } */
-- 
2.43.0