[clang] [HLSL] Add RasterizerOrderedStructuredBuffer definition to HLSLExternalSemaSource (PR #113648)

[Helena Kotas via cfe-commits]

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@@ -559,7 +559,7 @@ class CompilerInstance : public ModuleLoader {
   bool hasSema() const { return (bool)TheSema; }
 
   Sema &getSema() const {
-    assert(TheSema && "Compiler instance has no Sema object!");
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hekota wrote:

Oops, this should not be there! :)

https://github.com/llvm/llvm-project/pull/113648