[clang] [clang] Remove separate evaluation step for static class member init. (PR #142713)

[Eli Friedman via cfe-commits]

efriedma-quic wrote:

https://llvm-compile-time-tracker.com/compare.php?from=d204aa9deb72b8dcaf5e5b5550871d0ebe982825&to=9bc16d5c3b3c540ca3058e181b509f4122a2073b&stat=instructions:u .  Basically no change... which is what I was expecting.  There's maybe some slight savings from skipping the call to isIntegerConstantExpr().

https://github.com/llvm/llvm-project/pull/142713