Issues with compiler flags in gfortran

[Ken Cunningham]

> On Jan 23, 2019, at 00:06, Joshua Root <jmr at macports.org> wrote:
> 
> '--with-as=${prefix}/bin/llvm-as-mp-7.0'

1. have to be sure we're not talking about the assembler for llvm IR here, which is a totally different thing...I think we call clang.

2. bootstrapping. the stock toolchain on many systems can't build llvm 7.0, but also you don't want to be stuck with llvm-3.4's clang forever as the assembler on those systems either either.

The current system already would be better than that. 

K