[llvm] [UTC] Escape multiple {{ or }} in input for check lines. (PR #71790)

[Florian Hahn via llvm-commits]

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@@ -81,7 +81,7 @@ define void @test_brace_escapes(ptr noundef %arr) {
 ; CHECK-NEXT:      Grouped accesses:
 ; CHECK-NEXT:        Group [[GRP4]]:
 ; CHECK-NEXT:          (Low: {(64 + %arr),+,64}<%loop.1> High: {(8064 + %arr),+,64}<%loop.1>)
-; CHECK-NEXT:            Member: {{(64 + %arr),+,64}<%loop.1>,+,8}<%loop.2>
+; CHECK-NEXT:            Member: {{\{{}}(64 + %arr),+,64}<%loop.1>,+,8}<%loop.2>
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fhahn wrote:

It works for {{, but not for `{{{` or more. I updated the code to use a replacement function that escapes each { in the sequence; not sure if there's some python regex magic that does that without a separate function

https://github.com/llvm/llvm-project/pull/71790