fix: resolve coverage profile symbol at runtime

apps/macos/Tests/ClawdisIPCTests/CoverageDumpTests.swift

@@ -6,13 +6,19 @@ import Testing
 struct CoverageDumpTests {
     @Test func periodicallyFlushCoverage() async {
         guard ProcessInfo.processInfo.environment["LLVM_PROFILE_FILE"] != nil else { return }
+        guard let writeProfile = resolveProfileWriteFile() else { return }
         let deadline = Date().addingTimeInterval(4)
         while Date() < deadline {
-            _ = llvmProfileWriteFile()
+            _ = writeProfile()
             try? await Task.sleep(nanoseconds: 250_000_000)
         }
     }
 }
 
-@_silgen_name("__llvm_profile_write_file")
-private func llvmProfileWriteFile() -> Int32
+private typealias ProfileWriteFn = @convention(c) () -> Int32
+
+private func resolveProfileWriteFile() -> ProfileWriteFn? {
+    let symbol = dlsym(UnsafeMutableRawPointer(bitPattern: -2), "__llvm_profile_write_file")
+    guard let symbol else { return nil }
+    return unsafeBitCast(symbol, to: ProfileWriteFn.self)
+}