Merge pull request #3810 from tgross35/backport-haiku-b_app_image_symbol

[0.2] haiku: add B_APP_IMAGE_SYMBOL definition

Author: tgross35

src/unix/haiku/native.rs

@@ -956,6 +956,7 @@ pub const B_XATTR_TYPE: u32 = haiku_constant!('X', 'A', 'T', 'R');
 pub const B_NETWORK_ADDRESS_TYPE: u32 = haiku_constant!('N', 'W', 'A', 'D');
 pub const B_MIME_STRING_TYPE: u32 = haiku_constant!('M', 'I', 'M', 'S');
 pub const B_ASCII_TYPE: u32 = haiku_constant!('T', 'E', 'X', 'T');
+pub const B_APP_IMAGE_SYMBOL: *const ::c_void = core::ptr::null();
 
 extern "C" {
     // kernel/OS.h