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

[Brandon Wu via cfe-commits]

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@@ -854,6 +895,30 @@ 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");
+  std::string NewArch;
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4vtomat wrote:

`NewArch` might be assigned twice, I'm wondering whether we can pre-reserve a chunk of memory beforehand to prevent 1 more memory allocation?

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