Disable Ctrl-C handling in launcher when starting subprocess.

Fixes jruby/jruby#4519.

Author: headius

jvmlauncher.cpp

@@ -410,6 +410,11 @@ bool JvmLauncher::startOutProcJvm(const char *mainClassName, std::list<std::stri
         return false;
     }
 
+    // disable Ctrl-C handling in the parent process
+    if (!SetConsoleCtrlHandler(NULL, TRUE)) {
+	logErr(true, true, "Failed to disable Ctrl-C handling; Ctrl-C may behave oddly: %d", GetLastError());
+    }
+
     disableFolderVirtualization(pi.hProcess);
     ResumeThread(pi.hThread);
     WaitForSingleObject(pi.hProcess, INFINITE);