[clang] [OpenMP] Support for `nothing` in `metadirective` (PR #73690)

[Alexey Bataev via cfe-commits]

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@@ -12,7 +12,6 @@ int mixed() {
     x=d;
   }
 
-// expected-error at +2 {{#pragma omp nothing' cannot be an immediate substatement}}
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alexey-bataev wrote:

3 Directive and Construct Syntax
Neither a stand-alone directive nor a declarative directive may be used in place of a substatement
15 in a selection statement or iteration statement, or in place of the statement that follows a label.

https://github.com/llvm/llvm-project/pull/73690