build_llvm.py: Speed up llvm build with multi procs on windows (#3512)

ATTRIBUTIONS.md

@@ -18,7 +18,7 @@ WAMR project reused some components from other open source project:
 - **NuttX ELF headers**: used in core/iwasm/aot/debug/elf_parser.c
 - **Dhrystone**: for the test benchmakr dhrystone
 
-The WAMR fast interpreter is a clean room development. We would acknowledge the inspirations by [WASM3](https://github.com/wasm3/wasm3) open source project for the approach of pre-calculated oprand stack location.
+The WAMR fast interpreter is a clean room development. We would acknowledge the inspirations by [WASM3](https://github.com/wasm3/wasm3) open source project for the approach of pre-calculated operand stack location.
 
 |  third party components | version number | latest release | vendor pages | CVE details |
 | --- | --- | --- | --- | --- |

build-scripts/build_llvm.py

@@ -156,11 +156,15 @@ def build_llvm(llvm_dir, platform, backends, projects, use_clang=False, extra_fl
             CONFIG_CMD += " -A x64"
     else:
         CONFIG_CMD += " -G'Ninja'"
+    print(f"Config command: {CONFIG_CMD}")
     subprocess.check_call(shlex.split(CONFIG_CMD), cwd=build_dir)
 
     BUILD_CMD = "cmake --build . --target package" + (
         " --config Release" if "windows" == platform else ""
     )
+    if "windows" == platform:
+        BUILD_CMD += " --parallel " + str(os.cpu_count())
+    print(f"Build command: {BUILD_CMD}")
     subprocess.check_call(shlex.split(BUILD_CMD), cwd=build_dir)
 
     return build_dir