Update musl build instructions

[kiwidoggie]

Hello, I am currently stuck on these instructions, they appear to be really out of date: https://wiki.musl-libc.org/building-llvm.html

I'm unsure of what needs to be changed in order for it to build correctly, I've tried building on my own and I keep getting gnu dependencies being brought into the project.

[chaozju]

@kiwidoggie
Hi Did you find a way to fix these step?

These .S seem to no-longer be there.

curl -LO https://raw.github.com/path64/compiler/master/src/csu/elf-x86_64/crtbegin.S
curl -LO https://raw.github.com/path64/compiler/master/src/csu/elf-x86_64/crtend.S

as ../crtbegin.S -o /lib/clang/3.4/crtbegin.o
ln /lib/clang/3.4/crtbegin.o /lib/clang/3.4/crtbeginS.o
ln /lib/clang/3.4/crtbegin.o /lib/clang/3.4/crtbeginT.o
as ../crtend.S -o /lib/clang/3.4/crtend.o
ln /lib/clang/3.4/crtend.o /lib/clang/3.4/crtendS.o
ln /lib/clang/3.4/crtend.o /lib/clang/3.4/crtendT.o

[kiwidoggie]

@chaozju I have not sadly