Rollup merge of #122567 - erikdesjardins:noname, r=oli-obk

Remove fixme about LLVM basic block naming

~This may be a small perf win.~

Originally, this PR implemented the fixme, but it didn't have any measurable perf improvement.

r? ``@ghost``

Author: matthiaskrgr

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -1688,7 +1688,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     pub fn try_llbb(&mut self, bb: mir::BasicBlock) -> Option<Bx::BasicBlock> {
         match self.cached_llbbs[bb] {
             CachedLlbb::None => {
-                // FIXME(eddyb) only name the block if `fewer_names` is `false`.
                 let llbb = Bx::append_block(self.cx, self.llfn, &format!("{bb:?}"));
                 self.cached_llbbs[bb] = CachedLlbb::Some(llbb);
                 Some(llbb)