[llvm] [TargetParser] Parse Amazon Linux triple and handle RuntimeLibcalls (PR #136114)

[Fangrui Song via llvm-commits]

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@@ -173,7 +173,7 @@ void RuntimeLibcallsInfo::initLibcalls(const Triple &TT) {
     setLibcallName(RTLIB::EXP10_F64, "__exp10");
   }
 
-  if (TT.isGNUEnvironment() || TT.isOSFuchsia() ||
+  if (TT.isGNUEnvironment() || TT.isOSFuchsia() || TT.isAmazonLinux() ||
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MaskRay wrote:

Adding a TT.isAmazonLinux() condition doesn't scale as there are many isGNUEnvironment conditions.

Ideally you should switch to `aarch64-amazon-linux-gnu`. As an alternative (but it's not a good idea to not switch to `linux-gnu`, set `Environment` to GNU, perhaps in `Triple::Triple`.

https://github.com/llvm/llvm-project/pull/136114