Implement invokeNative asm code for MinGW (#1753)

And update the document of building iwasm for MinGW.

doc/build_wamr.md

@@ -382,6 +382,8 @@ are valid for the MSYS2 build environment:
 ```Bash
 pacman -R cmake
 pacman -S mingw-w64-x86_64-cmake
+pacman -S mingw-w64-x86_64-gcc
+pacman -S make git
 ```
 
 Then follow the build instructions for Windows above, and add the following
@@ -389,16 +391,15 @@ arguments for cmake:
 
 ```Bash
 cmake .. -G"Unix Makefiles" \
-         -DWAMR_BUILD_LIBC_UVWASI=0 \
-         -DWAMR_BUILD_INVOKE_NATIVE_GENERAL=1 \
          -DWAMR_DISABLE_HW_BOUND_CHECK=1
 ````
 
 Note that WASI will be disabled until further work is done towards full MinGW support.
 
-- uvwasi not building out of the box, though it reportedly supports MinGW.
-- Failing compilation of assembler files, the C version of `invokeNative()` will
-be used instead.
+- Since memory access boundary check with hardware trap feature is disabled, when generating the AOT file with `wamrc`, the `--bounds-checks=1` flag should be added to generate the memory access boundary check instructions to ensure the sandbox security:
+```bash
+wamrc --bounds-checks=1 -o <aot_file> <wasm_file>
+```
 - Compiler complaining about missing `UnwindInfoAddress` field in `RUNTIME_FUNCTION`
 struct (winnt.h).