Libunwind customizations for linking with x86_64-fortanix-unknown-sgx Rust target.

Description

Initial Fork

Initial Fork has been made from 5.0 release of llvm (commit: 6a075b6de4)

Detailed Description

Header files that we do not include for this target

1. pthread.h

Library that we do not link to for this target.

1. pthread (Locks used by libunwind is provided by rust stdlib for this target)

Building unwind for rust-sgx target

Generate Make files:

• cd where you want to build libunwind
• mkdir build
• cd build
• cmake -DCMAKE_BUILD_TYPE="RELEASE" -DRUST_SGX=1 -G "Unix Makefiles" -DLLVM_ENABLE_WARNINGS=1 -DLIBUNWIND_ENABLE_PEDANTIC=0 -DLLVM_PATH=<path/to/llvm> <path/to/libunwind>
• "DEBUG" could be used instead of "RELEASE" to enable debug logs of libunwind.

Build:

• make unwind_static
• build/lib/ will have the built library.