[clang] [llvm] [RISCV] Support RISC-V Profiles in -march option (PR #76357)

[Wang Pengcheng via cfe-commits]

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@@ -839,6 +860,33 @@ RISCVISAInfo::parseArchString(StringRef Arch, bool EnableExperimentalExtension,
                              "string must be lowercase");
   }
 
+  bool IsProfile = Arch.starts_with("rvi") || Arch.starts_with("rva") ||
+                   Arch.starts_with("rvb") || Arch.starts_with("rvm");
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wangpc-pp wrote:

RV[A|B|M]23 haven't been ratified, but I can add them as well.
`RVB` means some low-end APs I think?

https://github.com/llvm/llvm-project/pull/76357