wamr: remove dependency on LLVM. (#239)

WAMR is being used in an interpreter mode, without AOT and/or JIT,
so LLVM isn't needed, and it was previously unnecessarily built.

This can be reverted once we add support for precompiled modules.

Signed-off-by: Piotr Sikora <[email protected]>

Author: PiotrSikora

bazel/external/llvm13.BUILD

@@ -12,7 +12,6 @@ filegroup(
 cmake(
     name = "wamr_lib",
     cache_entries = {
-        "LLVM_DIR": "$EXT_BUILD_DEPS/copy_llvm13/llvm/lib/cmake/llvm",
         "WAMR_BUILD_INTERP": "1",
         "WAMR_BUILD_FAST_INTERP": "1",
         "WAMR_BUILD_JIT": "0",
@@ -26,7 +25,4 @@ cmake(
     generate_args = ["-GNinja"],
     lib_source = ":srcs",
     out_static_libs = ["libvmlib.a"],
-    deps = [
-        "@llvm13//:llvm_lib",
-    ],
 )

bazel/external/llvm13.patch

@@ -155,17 +155,6 @@ def proxy_wasm_cpp_host_repositories():
         actual = "@com_github_bytecodealliance_wasm_micro_runtime//:wamr_lib",
     )
 
-    maybe(
-        http_archive,
-        name = "llvm13",
-        build_file = "@proxy_wasm_cpp_host//bazel/external:llvm13.BUILD",
-        sha256 = "408d11708643ea826f519ff79761fcdfc12d641a2510229eec459e72f8163020",
-        strip_prefix = "llvm-13.0.0.src",
-        url = "https://github.com/llvm/llvm-project/releases/download/llvmorg-13.0.0/llvm-13.0.0.src.tar.xz",
-        patches = ["@proxy_wasm_cpp_host//bazel/external:llvm13.patch"],
-        patch_args = ["-p1"],
-    )
-
     # Wasmtime with dependencies.
 
     maybe(