jdk.jpackage/share/native/applauncher/JvmLauncher.cpp fails to build with GCC 6.3.0

Happens after JDK-8274856, seems like a missing #include.

* For target support_native_jdk.jpackage_libjpackageapplauncheraux_JvmLauncher.o:
src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp: In member function 'int {anonymous}::JliLaunchData::initJvmlLauncherData(JvmlLauncherData*) const':
src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp:289:54: error: expected primary-expression before ',' token
                             offsetof(JvmlLauncherData, jliLaunchArgv), curPtr);
                                                      ^
src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp:289:56: error: 'jliLaunchArgv' was not declared in this scope
                             offsetof(JvmlLauncherData, jliLaunchArgv), curPtr);
                                                        ^~~~~~~~~~~~~
src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp:289:69: error: 'offsetof' was not declared in this scope
                             offsetof(JvmlLauncherData, jliLaunchArgv), curPtr);
                                                                     ^
src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp:300:54: error: expected primary-expression before ',' token
                             offsetof(JvmlLauncherData, envVarNames), curPtr);
                                                      ^
src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp:310:54: error: expected primary-expression before ',' token
                             offsetof(JvmlLauncherData, envVarValues), curPtr);
   ... (rest of output omitted)