main/*: Add loongarch64 support to musl, binutils and gcc

Add loongarch64 support to musl, binutils and gcc.

• main/musl: add loongarch64 for APKBUILD.

• main/binutils:

1. disable gold for loongarch64
2. LoongArch: Modify inconsistent behavior of ld with --unresolved-symbols=ignore-all Patch backported from https://patchwork.sourceware.org/project/binutils/patch/20240226031135.841416-1-fanpeng@loongson.cn/

• main/gcc:

1. disable multilib support for loongarch64
2. LoongArch: Modify MUSL_DYNAMIC_LINKER Patch backported from: https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616145.html https://gcc.gnu.org/pipermail/gcc-patches/2023-November/637113.html