Fix the same issue for captures in atomic groups

Author: natecook1000

Sources/_StringProcessing/ByteCodeGen.swift

@@ -386,7 +386,7 @@ fileprivate extension Compiler.ByteCodeGen {
     builder.buildSave(intercept)
     try emitNode(child)
     builder.buildClearThrough(intercept)
-    builder.buildFail()
+    builder.buildFail(preservingCaptures: true) // Atomic group succeeds here
 
     builder.label(intercept)
     builder.buildClear()

Tests/RegexTests/MatchTests.swift

@@ -1804,8 +1804,7 @@ extension RegexTests {
     firstMatchTests(
       #"(?>(\d+))\w+\1"#,
       (input: "23x23", match: "23x23"),
-      (input: "123x23", match: "23x23"),
-      xfail: true)
+      (input: "123x23", match: "23x23"))
 
     // Backreferences in scalar mode
     // In scalar mode the backreference should not match