We're now hitting this because we're at the limit for number of builtins:
clang/lib/Basic/IdentifierTable.cpp:39:1: error: static_assert failed due to requirement '2 * LargestBuiltinID < (2 << (ObjCOrBuiltinIDBits - 1))' "Insufficient ObjCOrBuiltinID Bits"
static_assert(2 * LargestBuiltinID < (2 << (ObjCOrBuiltinIDBits - 1)),
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Bump it to 15 so whoever adds a builtin next (as I am, or as anyone else might) doesn't merge conflict over each other.
/// of a pointer to one of these classes.
enum { IdentifierInfoAlignment = 8 };
-static constexpr int ObjCOrBuiltinIDBits = 14;
+static constexpr int ObjCOrBuiltinIDBits = 15;
/// One of these records is kept for each identifier that
/// is lexed. This contains information about whether the token was \#define'd,