Update MinGW details in the README

[steveklabnik]

Fixes#29649

r? @retep998@alexcrichton

[hanna-kruppe]

This is probably not intended.

[steveklabnik]

whoah, thanks. No idea how that happened.

[retep998]

The link on that page takes me to a sourceforge download. I can't say I'm too happy about sourceforge (ublock blocks it saying it is badware), but then again, msys2 has to be obtained through sourceforge as well.

Also, a bit further down, the readme already describes how to obtain an alternate mingw-w64 due to issues with the mingw-w64 provided by msys2. At the very least you could consolidate that with the new information you're providing instead of having two separate somewhat redundant paragraphs.

If you feel up to it, could you add some more information clarifying that mingw-w64 only needs to be installed when building the -gnu targets and that when building the -msvc targets the user needs to have either VS 2013 or VS 2015 with the C++ stuff installed instead. Also the -msvc targets need to have cmake installed to build LLVM. -gnu may need cmake too, I don't know whether we've transitioned to using cmake for LLVM on all targets yet or just -msvc still.

[pitdicker]

It is just a detail, but I was confused whether I should choose the right msys flavor on Sourceforge or in the installer. Can you say "and choose the threads=win32,exceptions=dwarf/seh flavor in the installer"?

[steveklabnik]

Updated! I took some text from the install page.

[retep998]

Note that Msys2 still need to be installed, even when building the msvc targets, at least until @alexcrichton 's cargoified version of Rust is ready.

[brson]

@bors r+

[bors]

📌 Commit 011a23e has been approved by brson

[nrc]

r? @brson (just testing highfive)

[steveklabnik]

@bors: rollup