[liftoff] Pre-reserve some space for OOL code

The {AddOutOfLineTrap} method shows up with several percent of runtime
in performance profiles. The majority of that was spent copying entries
when growing the underlying vector.
Pre-reserving space in that vector removes most of that overhead.

R=thibaudm@chromium.org

Change-Id: I1befb75b070d4f803770c2afcc5c82ffb9bfb522
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3688511Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80943}

src/wasm/baseline/liftoff-compiler.cc

@@ -511,6 +511,11 @@ class LiftoffCompiler {
         handlers_(compilation_zone),
         max_steps_(options.max_steps),
         nondeterminism_(options.nondeterminism) {
+    // We often see huge numbers of traps per function, so pre-reserve some
+    // space in that vector. 128 entries is enough for ~94% of functions on
+    // modern modules, as of 2022-06-03.
+    out_of_line_code_.reserve(128);
+
     DCHECK(options.is_initialized());
     // If there are no breakpoints, both pointers should be nullptr.
     DCHECK_IMPLIES(