fix windows gnu build

[thewh1teagle]

I tried to use this library on windows inside msys2, following BUILDING.md and got bunch of erros.
Fixed all of them and planning to improve the instructions as well.
Checked in msys2 and it works with the examples of this repo.

#87
#65

Steps to build:

1. Download msys2 from https://www.msys2.org/ and install
2. Install prerequisites from ucrt64 terminal

pacman --needed -S $MINGW_PACKAGE_PREFIX-{toolchain,make,cmake,rust,clang} git

3. Clone

git clone -b fix/msys2-build --recursive https://github.com/thewh1teagle/whisper-rs.git
cd whisper-rs

4. Build

cargo build

5. Try it

wget -q --show-progress \
    https://huggingface.co/ggerganov/whisper.cpp/resolve/main/ggml-base.en.bin -O ggml-base.en.bin
cd examples/full_usage
cargo run 2830-3980-0043.wav ../../ggml-base.en.bin

[tazz4843]

Thanks :)