on top of 9b1620a501c1 (Clang, increase upper bound of partially initialized array sizes.) to close 57353.
RUN like is missing a target triple, so it will break if the compiler's default target isn't x86_64. RUN line is missing a FileCheck invocation, so nothing actually examines the CHECK lines. Look at other tests for examples.
Maybe the commit message ("summary") could use a bit more description. I'm not sure what 9b1620a501c1 refers to, and I'm not sure it's relevant.
Since you don't have commit access, I'll commit this for you when it's ready. How do you want to be credited in the "author" field of the git commit? (name+email)
Maybe CHECK-NEXT: .size bad_int, 4294967296, to be on the safe side. (The current version of the test would pass on a release build without your patch.)