https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102989
--- Comment #37 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- If _BitInt constants aren't INTEGER_CST, then all places that expect that any integer constant expression is folded to an INTEGER_CST will need updating to handle whatever tree code is used for _BitInt constants. (In some places that may be needed for correctness, in other places - where a large value wouldn't actually be valid - only for proper diagnostics about an invalid value, if INTEGER_CST is still used for smaller _BitInt constants.)
