Use bundled libunwind until at least

https://github.com/libunwind/libunwind/issues/715

is fixed. It is also believed that using bundled libunwind may help against
random crashes on amd64 too.

--- src/runtime/src/native/corehost/apphost/static/CMakeLists.txt.orig
+++ src/runtime/src/native/corehost/apphost/static/CMakeLists.txt
@@ -244,7 +244,7 @@ endif(CLR_CMAKE_TARGET_APPLE)

 # On *BSD, we always use the libunwind that's part of the OS
 if(CLR_CMAKE_TARGET_FREEBSD)
-  set(CLR_CMAKE_USE_SYSTEM_LIBUNWIND 1)
+  set(CLR_CMAKE_USE_SYSTEM_LIBUNWIND 0)
 endif()

 if(CLR_CMAKE_USE_SYSTEM_LIBUNWIND AND NOT CLR_CMAKE_TARGET_APPLE)

--- src/runtime/src/coreclr/pal/src/CMakeLists.txt.orig
+++ src/runtime/src/coreclr/pal/src/CMakeLists.txt
@@ -1,7 +1,7 @@
 if(CLR_CMAKE_TARGET_OSX OR CLR_CMAKE_TARGET_FREEBSD OR CLR_CMAKE_TARGET_HAIKU)
   # On OSX and *BSD, we use the libunwind that's part of the OS
   # On Haiku, we used a special port of libunwind
-  set(CLR_CMAKE_USE_SYSTEM_LIBUNWIND 1)
+  set(CLR_CMAKE_USE_SYSTEM_LIBUNWIND 0)
 endif(CLR_CMAKE_TARGET_OSX OR CLR_CMAKE_TARGET_FREEBSD OR CLR_CMAKE_TARGET_HAIKU)

 if(NOT DEFINED ENV{ROOTFS_DIR})

--- src/runtime/src/native/external/libunwind.cmake.orig
+++ src/runtime/src/native/external/libunwind.cmake
@@ -96,7 +96,7 @@ elseif(CLR_CMAKE_TARGET_FREEBSD)
     set(libunwind_la_SOURCES_arm_os             arm/Gos-freebsd.c)
     set(libunwind_la_SOURCES_arm_os_local       arm/Los-freebsd.c)
     set(libunwind_la_SOURCES_aarch64_os         aarch64/Gos-freebsd.c)
-    set(libunwind_la_SOURCES_aarch64_os_local   aarch64/Los-freebsd.c)
+    set(libunwind_la_SOURCES_aarch64_os_local   aarch64/Los-freebsd.c aarch64/setcontext.S)
     list(APPEND libunwind_coredump_la_SOURCES   coredump/_UCD_access_reg_freebsd.c)
 elseif(CLR_CMAKE_HOST_SUNOS)
     set(libunwind_la_SOURCES_os                 ${libunwind_la_SOURCES_os_solaris})