[test] Add regression test for SR-307

Author: hamishknight

test/Profiler/issue-42929.swift

@@ -0,0 +1,39 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %s -profile-generate -profile-coverage-mapping -o %t/main
+
+// This unusual use of 'sh' allows the path of the profraw file to be
+// substituted by %target-run.
+// RUN: %target-codesign %t/main
+// RUN: %target-run sh -c 'env LLVM_PROFILE_FILE=$1 $2' -- %t/default.profraw %t/main
+
+// RUN: %llvm-profdata merge %t/default.profraw -o %t/default.profdata
+// RUN: %llvm-cov export -summary-only %t/main -instr-profile=%t/default.profdata | %FileCheck %s
+
+// REQUIRES: profile_runtime
+// REQUIRES: executable_test
+// REQUIRES: objc_interop
+// REQUIRES: OS=macosx
+
+// https://github.com/apple/swift/issues/42929
+
+// There are actually only 14 lines here, but llvm-cov doesn't handle closures
+// properly (rdar://90348983).
+// CHECK: "lines":{"count":18,"covered":18{{.*}}"functions":{"count":7,"covered":7
+
+import Foundation
+
+func foo(_ x: @autoclosure () -> Bool) { _ = x() }
+
+func bar() {
+  foo(.random())
+  foo(.random())
+
+  class C : NSObject {
+    class D : NSObject {
+    }
+  }
+
+  foo(.random())
+  foo(.random())
+}
+bar()