Remove obsolete doc about -faddrsig.

Test: None
Bug: android/ndk#884
Change-Id: Ic28588cc1ce433d8ccb0ef39c502479885bcdb61

docs/BuildSystemMaintainers.md

@@ -353,10 +353,6 @@ Android requires [Position-independent executables] beginning with API 21. Clang
 builds PIE executables by default. If invoking the linker directly or not using
 Clang, use `-pie` when linking.
 
-Clang uses `-faddrsig` by default, but this produces output that is incompatible
-with GNU binutils. To workaround this, `-fno-addrsig` must be passed to Clang
-when using GNU binutils. See [Issue 884].
-
 Clang does not properly set the ARMv7 architecture for the non-integrated
 assembler. If using `-fno-integrated-as`, you must explicitly pass
 `-march=armv7-a` when compiling for 32-bit ARM. Note that by default Clang will
@@ -375,7 +371,6 @@ version of LLDB doesn't recognize LLD's default 8-byte build ID. See [Issue
 885].
 
 [Issue 635]: https://github.com/android-ndk/ndk/issues/635
-[Issue 884]: https://github.com/android-ndk/ndk/issues/884
 [Issue 885]: https://github.com/android-ndk/ndk/issues/885
 [Issue 906]: https://github.com/android-ndk/ndk/issues/906
 [Issue 1004]: https://github.com/android-ndk/ndk/issues/1004