[llvm] [clang] [RISCV] Add MC layer support for Zicfiss. (PR #66043)

[Yeting Kuo via cfe-commits]

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@@ -1024,6 +1024,7 @@ static const char *ImpliedExtsZfinx[] = {"zicsr"};
 static const char *ImpliedExtsZhinx[] = {"zhinxmin"};
 static const char *ImpliedExtsZhinxmin[] = {"zfinx"};
 static const char *ImpliedExtsZicntr[] = {"zicsr"};
+static const char *ImpliedExtsZicfiss[] = {"zicsr", "zimop", "zcmop"};
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yetingk wrote:

I add a patch to not imply Zcmop and enable c.sspush when Zcmop enabled.

https://github.com/llvm/llvm-project/pull/66043