[llvm] [Runtimes] Rework and remove default runtimes build (PR #158156)

[Michael Kruse via llvm-commits]

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@@ -318,8 +241,12 @@ function(runtime_register_target name)
     set(install-${runtime_name}-${name}-stripped install-${runtime_name}-stripped)
     list(APPEND ${name}_extra_targets ${runtime_name}-${name} install-${runtime_name}-${name} install-${runtime_name}-${name}-stripped)
     if(LLVM_INCLUDE_TESTS)
-      set(check-${runtime_name}-${name} check-${runtime_name} )
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Meinersbur wrote:

[nit] unrelated change

https://github.com/llvm/llvm-project/pull/158156