LibWasm: Generate all spec tests, even ones that aren't valid modules

`wasm-as` will do some semantic analysis on the modules, which is not
something we're looking for here.
Instead, use `wat2wasm` to generate the exact module.

.github/workflows/cmake.yml

@@ -196,15 +196,15 @@ jobs:
       run: |
         sudo apt-get purge -y clang-11
         sudo apt-get update
-        sudo apt-get install ninja-build binaryen
+        sudo apt-get install ninja-build wabt
         sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-12 100
         sudo update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-12 100
       if: ${{ runner.os == 'Linux' }}
     - name: Install macOS dependencies
-      run: brew install ninja binaryen
+      run: brew install ninja wabt
       if: ${{ runner.os == 'macOS' }}
     - name: Check versions
-      run: set +e; clang --version; clang++ --version; ninja --version; wasm-as --version
+      run: set +e; clang --version; clang++ --version; ninja --version; wat2wasm --version
 
     # === PREPARE FOR BUILDING ===
 

Meta/generate-libwasm-spec-test.py

@@ -380,7 +380,7 @@ def main():
             with NamedTemporaryFile("w+") as temp:
                 temp.write(mod[1])
                 temp.flush()
-                rc = call(["wasm-as", "-n", "-all", temp.name, "-o", outpath])
+                rc = call(["wat2wasm", temp.name, "-o", outpath])
                 if rc != 0:
                     print("Failed to compile", name, "module index", index, "skipping that test", file=stderr)
                     continue