[PATCH v2] RISC-V: Make PR 102957 tests more comprehensive

[Tsukasa OI <research_trasio@irq.a4lg.com>]

From: Tsukasa OI <research_trasio@irq.a4lg.com>

Commit c283c4774d1c ("RISC-V: Throw compilation error for unknown
extensions") changed how do we handle unknown extensions and
commit 6f709f79c915a ("[committed] [RISC-V] Fix expected diagnostic messages
in testsuite") "fixed" test failures caused by that change (on pr102957.c,
by testing the error message after the first change).

However, the latter change will partially break the original intent of PR
102957 test case because we wanted to make sure that we can parse a valid
two-letter extension name.

Fortunately, there is a valid two-letter extension name, 'Zk' (standard
scalar cryptography extension superset with NIST algorithm suite).

This commit adds pr102957-2.c to make sure that there will be no errors if
we parse a valid two-letter extension name.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/pr102957-2.c: New test case using the 'Zk'
	extension to continue testing whether we can use valid two-letter
	extensions.
---
 gcc/testsuite/gcc.target/riscv/pr102957-2.c | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/riscv/pr102957-2.c

diff --git a/gcc/testsuite/gcc.target/riscv/pr102957-2.c b/gcc/testsuite/gcc.target/riscv/pr102957-2.c
new file mode 100644
index 000000000000..fe6241466354
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/pr102957-2.c
@@ -0,0 +1,5 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gzk -mabi=lp64" } */
+int foo()
+{
+}

base-commit: 818cc9f2d2f3dbbd4004ff85d3125d92d1e430c9
-- 
2.42.0