Add loongarch64 support

[haowuge]

This PR allows using vcpkg on LoongArch machines (loongarch32/64). Tested with Gentoo Linux 2.14 (loongarch64 GNU/Linux / Loongson-3A5000-HV-7A2000-1w-V0.1-EVB)

Tested ports:

vcpkg list
7zip:loongarch64-linux                            22.01#1             Library for archiving file with a high compressi...
bzip2:loongarch64-linux                           1.0.8#4             bzip2 is a freely available, patent free, high-q...
bzip2[tool]:loongarch64-linux                                         Builds bzip2 executable
curl:loongarch64-linux                            8.2.0               A library for transferring data with URLs
curl[non-http]:loongarch64-linux                                      Enables protocols beyond HTTP/HTTPS/HTTP2
curl[openssl]:loongarch64-linux                                       SSL support (OpenSSL)
curl[ssl]:loongarch64-linux                                           Default SSL backend
cxxopts:loongarch64-linux                         3.1.1               This is a lightweight C++ option parser library,...
fmt:loongarch64-linux                             10.0.0              Formatting library for C++. It can be used as a ...
magic-enum:loongarch64-linux                      0.9.2               Header-only C++17 library provides static reflec...
openssl:loongarch64-linux                         3.1.1#1             OpenSSL is an open source project that provides ...
vcpkg-cmake-config:loongarch64-linux              2022-02-06#1        
vcpkg-cmake-get-vars:loongarch64-linux            2023-03-02          
vcpkg-cmake:loongarch64-linux                     2023-05-04          
yasm:loongarch64-linux                            1.3.0#5             Yasm is a complete rewrite of the NASM assembler...
yasm[tools]:loongarch64-linux                                         Build yasm tools
zlib:loongarch64-linux                            1.2.13              A compression library

[haowuge]

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[haowuge]

@microsoft-github-policy-service agree

[BillyONeal]

You said you tested on Gentoo but the edits are in coffilereader which I don't believe is used on Linux... what input did this get tested on?

[BillyONeal]

You said you tested on Gentoo but the edits are in coffilereader which I don't believe is used on Linux... what input did this get tested on?

To clarify, I'm just trying to understand what testing was done, not necessarily that any code needs to change. If we don't have testing of a loongarch Windows binary but we're just adding a value to a table that's documented in the official spec and not otherwise using the result, that can be OK; I just wanted to make sure I understood the situation.

[BillyONeal]

Thanks :)