[PPC] Remove Julia address-spaces before machine codegen

[vchuravy]

Might fix #45019

[staticfloat]

Looks like progress! We're now failing on some float16 functions, I think.

https://buildkite.com/julialang/julia-buildkite/builds/571#01812575-c314-4cda-940b-8c96075ef79a/361-2629

...
float.jl
JIT session error: Symbols not found: [ __gnu_f2h_ieee, __gnu_h2f_ieee ]
Failure value returned from cantFail wrapped call
Failed to materialize symbols: { (JuliaOJIT, { julia_Float16_2934, jfptr_Float16_2935 }) }
UNREACHABLE executed at /cache/build/default-ppcbot2-0/julialang/julia-buildkite/usr/include/llvm/Support/Error.h:782!

[staticfloat]

Alright, I've got your PR here set to pull JuliaCI/julia-buildkite#119 as its CI configuration; so you can push things to this branch and it will only test on ppc64le-linux-gnu and x86_64-linux-gnu for now.

[vchuravy]

Grrml @vtjnash

JIT session error: Symbols not found: [ __gnu_f2h_ieee, __gnu_h2f_ieee ]

[vchuravy]

So we are still generating:

Executing precompile statements... 1438/1919
Intrinsic has incorrect argument type!
void ({} addrspace(10)*)* @llvm.ppc.cfence.p10sl_s

:/

[vchuravy]

Huh. Address space 0 is also not allowed?

void ({}) @llvm.ppc.cfence.p0sl_s

[giordano]

Is this PR superseded by #45755 and #45761 or it's relevant anyway?

[vchuravy]

There is still some funkiness with that pass, but this should hopefully not be necessary