[clang] [clang] Add support for SerenityOS (PR #187941)

[Fangrui Song via cfe-commits]

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@@ -30,6 +30,8 @@
 // RUN: %clang --target=x86_64-unknown-fuchsia -save-stats -flto -o obj/dir/save-stats.exe -Wl,-plugin-opt=-dummy %s -### 2>&1 | FileCheck %s -check-prefix=CHECK-LTO
 // RUN: %clang --target=x86_64-unknown-haiku -save-stats -flto -o obj/dir/save-stats.exe %s -### 2>&1 | FileCheck %s -check-prefix=CHECK-LTO
 // RUN: %clang --target=x86_64-unknown-haiku -save-stats -flto -o obj/dir/save-stats.exe -Wl,-plugin-opt=-dummy %s -### 2>&1 | FileCheck %s -check-prefix=CHECK-LTO
+// RUN: %clang --target=x86_64-unknown-serenity -save-stats -flto -o obj/dir/save-stats.exe %s -### 2>&1 | FileCheck %s -check-prefix=CHECK-LTO
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MaskRay wrote:

Delete. No need to add more tests to this generic feature. fuchsia/haiku are not good models to follow here.

https://github.com/llvm/llvm-project/pull/187941