[DO NOT MERGE] break codegen test

[RalfJung]

This is just to see if I can reproduce the problem I noticed in #51361 where a codegen test was failing for pre-bors CI did not catch it.

[rust-highfive]

r? @nikomatsakis

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[bjorn3]

Travis is green!!!

[eddyb]

There's a // min-llvm-version 6.0 at the top of the file, that's why.

[RalfJung]

But why does the CI runner not use the same LLVM version as x.py?

Cc @rust-lang/infra

[Mark-Simulacrum]

We have different CI runners; one of them tests against the baseline LLVM (currently 5.0) whereas the rest test against the in-tree LLVM, which is ~7.0 at this point (well, master at some recent date) I believe.

[eddyb]

@RalfJung It's intentional (IIRC it avoids building LLVM ourselves by using the system one):

rust/.travis.yml

Lines 18 to 20 in 75af9df

	# Images used in testing PR and try-build should be run first.
	- env: IMAGE=x86_64-gnu-llvm-5.0 RUST_BACKTRACE=1
	if: type = pull_request OR branch = auto

[RalfJung]

I see. Probably we were just unlucky then, with this bug slipping through until main bors time?

Anyway, if there's no bug, I guess we can close this?