Currently, clang does not emit the mustprogress loop or function
attribute for loops with non-zero constant conditionals. Based on recent
discussion in D86844 and D86841, it seems that it would be preferable to
emit these attributes to adhere more tightly to the C++ standard as gcc
I will be pushing a patch to add -ffinite-loops and -fno-finite-loops to
clang to provide more control over this momentarily.