[clang] [llvm] [SYCL] Shorten triple form in device binary. (PR #231446)

[Kseniya Tikhomirova via cfe-commits]

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@@ -1043,8 +1043,12 @@ static Error runSYCLLink(ArrayRef<std::unique_ptr<MemoryBuffer>> Inputs,
     OffloadingImage TheImage{};
     TheImage.TheImageKind = IsAOTCompileNeeded ? IMG_Object : IMG_SPIRV;
     TheImage.TheOffloadKind = OFK_SYCL;
+    // Pack the short form of the triple. The runtime only needs to know which
+    // binary format the image holds, and the architecture is the single
+    // canonical spelling of it: inputs may spell the same target as 'spirv64'
+    // or 'spirv64-unknown-unknown'.
     TheImage.StringData["triple"] =
-        Args.MakeArgString(Result.TargetTriple.str());
+        Args.MakeArgString(Result.TargetTriple.getArchName());
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KseniyaTikhomirova wrote:

I fill I am missing something here. @bader, what do you mean under "normalized" triple? How is it different from initial impl when we write "spirv64-unknown-unknown"? From what I see in class Triple, normalize(...) has forms:
  ```
/// Canonical form
  enum class CanonicalForm {
    ANY = 0,
    THREE_IDENT = 3, // ARCHITECTURE-VENDOR-OPERATING_SYSTEM
    FOUR_IDENT = 4,  // ARCHITECTURE-VENDOR-OPERATING_SYSTEM-ENVIRONMENT
    FIVE_IDENT = 5,  // ARCHITECTURE-VENDOR-OPERATING_SYSTEM-ENVIRONMENT-FORMAT
  };
```
all of them have more data than I need.

about getArch() we talked with @YuriPlyakhin - it is kind of reserved for exact device arch (AOT) binary is built for. So it seems to be not a good place to pass target here.

https://github.com/llvm/llvm-project/pull/231446