Bug 1875002 - Explicitly set LIBCXXABI_USE_LLVM_UNWINDER off when building wasi-sdk. r=firefox-build-system-reviewers,sergesanspaille

Clang trunk has recently turned it on, and also now fails the build when
libunwind is not built at the same time.

Upstreamed in WebAssembly/wasi-sdk#377

Differential Revision: https://phabricator.services.mozilla.com/D198763

UltraBlame original commit: a4bff50d95674a402744d071f9d2b97b482452bb

Author: marco-c

taskcluster/scripts/misc/wasi-sdk.patch

@@ -4,6 +4,91 @@ diff
 git
 a
 /
+Makefile
+b
+/
+Makefile
+index
+d2ccff6
+.
+.
+95f395b
+100644
+-
+-
+-
+a
+/
+Makefile
++
++
++
+b
+/
+Makefile
+-
+178
+6
++
+178
+7
+LIBCXX_CMAKE_FLAGS
+=
+\
+-
+DLIBCXXABI_BUILD_EXTERNAL_THREAD_LIBRARY
+:
+BOOL
+=
+OFF
+\
+-
+DLIBCXXABI_HAS_WIN32_THREAD_API
+:
+BOOL
+=
+OFF
+\
+-
+DLIBCXXABI_ENABLE_PIC
+:
+BOOL
+=
+OFF
+\
++
+-
+DLIBCXXABI_USE_LLVM_UNWINDER
+:
+BOOL
+=
+OFF
+\
+-
+DWASI_SDK_PREFIX
+=
+(
+BUILD_PREFIX
+)
+\
+-
+DUNIX
+:
+BOOL
+=
+ON
+\
+-
+-
+debug
+-
+trycompile
+diff
+-
+-
+git
+a
+/
 src
 /
 wasi