[llvm] [TableGen] New tblgen Pattern bit to disable DAG pattern imports during GISel (PR #88382)

[via llvm-commits]

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@@ -4378,7 +4378,8 @@ void CodeGenDAGPatterns::ParsePatterns() {
       FindPatternInputsAndOutputs(Pattern, Pattern.getTree(j), InstInputs,
                                   InstResults, InstImpResults);
 
-    ParseOnePattern(CurPattern, Pattern, Result, InstImpResults);
+    if (!CurPattern->getValueAsBit("GISelShouldIgnore"))
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jofrn wrote:

Yes, that would affect it in this way, which isn't what we want... Reworking back to the prior commit.

https://github.com/llvm/llvm-project/pull/88382