Build LLDB as part of wasi-sdk

This is intended to provide a known-good build of LLDB with wasm plugin
support which can exist alongside the rest of the LLVM distribution
provided by wasi-sdk.

Author: alexcrichton

cmake/wasi-sdk-toolchain.cmake

@@ -33,7 +33,7 @@ foreach(target IN LISTS WASI_SDK_TARGETS)
   list(APPEND links_to_create ${target}-clang++)
 endforeach()
 
-set(projects "lld;clang;clang-tools-extra")
+set(projects "lld;clang;clang-tools-extra;lldb")
 
 set(tools
   clang
@@ -57,7 +57,8 @@ set(tools
   objdump
   objcopy
   c++filt
-  llvm-config)
+  llvm-config
+  lldb)
 
 # By default link LLVM dynamically to all the various tools. This greatly
 # reduces the binary size of all the tools through a shared library rather than
@@ -69,7 +70,7 @@ set(tools
 # `lib` dir gets put on `LD_LIBRARY_PATH` or similar.
 if(NOT WIN32)
   list(APPEND default_cmake_args -DLLVM_LINK_LLVM_DYLIB=ON -DLLVM_VERSION_SUFFIX=-wasi-sdk)
-  list(APPEND tools LLVM clang-cpp)
+  list(APPEND tools LLVM clang-cpp liblldb)
 endif()
 
 list(TRANSFORM tools PREPEND --target= OUTPUT_VARIABLE build_targets)
@@ -90,6 +91,8 @@ ExternalProject_Add(llvm-build
     -DLLVM_DEFAULT_TARGET_TRIPLE=wasm32-wasi
     -DLLVM_INSTALL_BINUTILS_SYMLINKS=TRUE
     -DLLVM_ENABLE_LIBXML2=OFF
+    -DLLDB_INCLUDE_TESTS=OFF
+    -DLLDB_INCLUDE_UNITTESTS=OFF
     # Pass `-s` to strip symbols by default and shrink the size of the
     # distribution
     -DCMAKE_EXE_LINKER_FLAGS=-s