1. [scudo][standalone] Fix tests under ASan/UBSan (details)
  2. Revert "[lsan] On Fuchsia, don't use atexit hook for leak checks" (details)
Commit 2efc09c90914a6c887cb772130d6b375a1713472 by kostyak
[scudo][standalone] Fix tests under ASan/UBSan

Fix a potential UB in `appendSignedDecimal` (with -INT64_MIN) by making
it a special case.

Fix the terrible test cases for `isOwned`: I was pretty sloppy on those
and used some stack & static variables, but since `isOwned` accesses
memory prior to the pointer to check for the validity of the Scudo
header, it ended up being detected as some global and stack buffer out
of bounds accesses. So not I am using buffers with enough room so that
the test will not access memory prior to the variables.

With those fixes, the tests pass on the ASan+UBSan Fuchsia build.

Thanks to Roland for pointing those out!

Differential Revision:
The file was modifiedcompiler-rt/lib/scudo/standalone/tests/combined_test.cpp (diff)
The file was modifiedcompiler-rt/lib/scudo/standalone/string_utils.cpp (diff)
Commit f161e84c10b6eb2255345ebfaaa2bbadb4b0fe2a by nikita.ppv
Revert "[lsan] On Fuchsia, don't use atexit hook for leak checks"

This reverts commit 0caad9fe441d5ee562e96d8b30b5574b492a933a.
This reverts commit c96d0cceb684fa176b51d7df5f4f8370e2c983f4.

Causes linker errors which were not fixed by the subsequent commit

/home/nikic/llvm-project/compiler-rt/lib/asan/asan_rtl.cpp:503: error: undefined reference to '__asan::InstallAtExitCheckLeaks()'
The file was modifiedcompiler-rt/lib/asan/asan_win.cpp (diff)
The file was modifiedcompiler-rt/lib/lsan/lsan.cpp (diff)
The file was modifiedcompiler-rt/lib/asan/asan_posix.cpp (diff)
The file was modifiedcompiler-rt/lib/lsan/lsan_posix.cpp (diff)
The file was modifiedcompiler-rt/lib/asan/asan_fuchsia.cpp (diff)
The file was modifiedcompiler-rt/lib/lsan/lsan.h (diff)
The file was modifiedcompiler-rt/lib/asan/asan_internal.h (diff)
The file was modifiedcompiler-rt/lib/asan/asan_rtl.cpp (diff)
The file was modifiedcompiler-rt/lib/lsan/lsan_fuchsia.cpp (diff)
The file was modifiedcompiler-rt/lib/lsan/lsan_common_fuchsia.cpp (diff)