Revert unwind detection logic changes

debian/changelog

@@ -1,9 +1,5 @@
 llvm-toolchain-16 (1:16.0.6-22) unstable; urgency=medium
 
-  [ Zixing Liu ]
-  * d/p/fix-unwind-detection-logic.patch: use an upstream patch to fix
-    libunwind detection logic when compiler-rt is disabled.
-
   [ Gianfranco Costamagna ]
   * Disable tests on mips64el
 

debian/patches/fix-unwind-detection-logic.patch

@@ -1,39 +0,0 @@
-From 7c5e4e5fa3a948fc662be3a6bf057021d32f72e6 Mon Sep 17 00:00:00 2001
-From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
-Date: Thu, 5 Oct 2023 11:41:11 +0300
-Subject: [PATCH] Reapply [compiler-rt] Check for and use -lunwind when linking
- with -nodefaultlibs (#66584)
-
-If libc++ is available and should be used as the ubsan C++ ABI library,
-the check for libc++ might fail if libc++ is a static library, as the
--nodefaultlibs flag inhibits a potential compiler default -lunwind.
-
-Just like the -nodefaultlibs configuration tests for and manually adds a
-bunch of compiler default libraries, look for -lunwind too.
-
-This is a reland of #65912.
----
- compiler-rt/cmake/config-ix.cmake | 10 ++++++++++
- 1 file changed, 10 insertions(+)
-
-diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
-index 09a9b62ce4cd37..a8e078f1ebc988 100644
---- a/compiler-rt/cmake/config-ix.cmake
-+++ b/compiler-rt/cmake/config-ix.cmake
-@@ -63,6 +63,16 @@ if (C_SUPPORTS_NODEFAULTLIBS_FLAG)
-                         moldname mingwex msvcrt)
-     list(APPEND CMAKE_REQUIRED_LIBRARIES ${MINGW_LIBRARIES})
-   endif()
-+  if (NOT TARGET unwind)
-+    # Don't check for a library named unwind, if there's a target with that name within
-+    # the same build.
-+    check_library_exists(unwind _Unwind_GetRegionStart "" COMPILER_RT_HAS_LIBUNWIND)
-+    if (COMPILER_RT_HAS_LIBUNWIND)
-+      # If we're omitting default libraries, we might need to manually link in libunwind.
-+      # This can affect whether we detect a statically linked libc++ correctly.
-+      list(APPEND CMAKE_REQUIRED_LIBRARIES unwind)
-+    endif()
-+  endif()
- endif ()
- 
- # CodeGen options.

debian/patches/series

@@ -135,7 +135,6 @@ protobuf_3.21.patch
 # compiler-rt
 compiler-rt/compilerrt-builtins-arch-fix-armhf.diff
 compiler-rt/compilerrt-build-scudo-standalone-option.diff
-fix-unwind-detection-logic.patch
 
 # wasm patches
 wasm/wasm-ld-path.diff