Add CSGetDebugLoggingLevel along with a semi-real test for it

Package.swift

@@ -13,6 +13,16 @@ let package = Package(
     ],
     targets: [
         .systemLibrary(name: "CoreSymbolication"),
+        .testTarget(name: "CoreSymbolicationTests",
+                    dependencies: ["CoreSymbolication"],
+                    linkerSettings: [
+                      .unsafeFlags([
+                        "-Xlinker", "-F",
+                        "-Xlinker", "/System/Library/PrivateFrameworks",
+                        "-Xlinker", "-framework",
+                        "-Xlinker", "CoreSymbolication",
+                      ]),
+                    ]),
     ],
     swiftLanguageVersions: [.v5]
-)
+)

Sources/CoreSymbolication/CoreSymbolication.h

@@ -34,6 +34,11 @@ CSTypeRef CSRetain(CSTypeRef cs);
 void CSRelease(CSTypeRef cs);
 void CSShow(CSTypeRef cs);
 
+typedef int CSDebugLogLevel;
+
+CSDebugLogLevel CSGetDebugLoggingLevel() API_AVAILABLE(macosx(12.0));
+void CSSetDebugLoggingLevel(CSDebugLogLevel level) API_AVAILABLE(macosx(12.0));
+
 typedef void (^CSSymbolicatorIterator)(CSSymbolicatorRef symbolicator);
 
 void CSSymbolicatorForeachSymbolicatorWithURL(CFURLRef url, CSSymbolicatorIterator it);

Tests/CoreSymbolicationTests/CoreSymbolicationTests.swift

@@ -0,0 +1,10 @@
+import XCTest
+@testable import CoreSymbolication
+
+final class CoreSymbolicationTests: XCTestCase {
+    func testLoggingLevelAvailability() {
+        if #available(macOS 12.0, *) {
+            _ = CSGetDebugLoggingLevel()
+        }
+    }
+}