[llvm] [SDAG] Promote extract subvector in more cases without falling back to build vectors. (PR #212156)

[Usman Nadeem via llvm-commits]

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@@ -6138,11 +6138,70 @@ SDValue DAGTypeLegalizer::PromoteIntRes_EXTRACT_SUBVECTOR(SDNode *N) {
   if (OutVT.isScalableVector())
     report_fatal_error("Unable to promote scalable types using BUILD_VECTOR");
 
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UsmanNadeem wrote:

Will later merge with the similar scalable code above.

https://github.com/llvm/llvm-project/pull/212156