[llvm] [DAG] computeKnownFPClass - add ISD::EXTRACT_VECTOR_ELT handling (PR #190307)

[Simon Pilgrim via llvm-commits]

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@@ -22,6 +22,168 @@ define i8 @iszero_constant_v4f32() nounwind {
   ret i8 %r
 }
 
+define i1 @extract_bitcast_sign_set_not_pos(<4 x i32> %bits, ptr %p) nounwind {  ; elts 0,2 sign set, idx=0, ispos -> false
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RKSimon wrote:

(style) move the test comments above the name:
```suggestion
; elts 0,2 sign set, idx=0, ispos -> false
define i1 @extract_bitcast_sign_set_not_pos(<4 x i32> %bits, ptr %p) nounwind {
```

https://github.com/llvm/llvm-project/pull/190307