[clang] [Driver] Teach Barmetal toolchain about GCC installation(1/3) (PR #121829)

[Petr Hosek via cfe-commits]

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@@ -97,7 +97,8 @@ static bool findRISCVMultilibs(const Driver &D,
   return false;
 }
 
-static std::string computeBaseSysRoot(const Driver &D, bool IncludeTriple) {
+static std::string computeInstalledToolchainSysRoot(const Driver &D,
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petrhosek wrote:

Can we avoid renaming this method? That doesn't seem to be necessary and it only creates unnecessary churn.

https://github.com/llvm/llvm-project/pull/121829