Add option to speed up Torque compilation

This change adds a flag v8_enable_fast_torque, which follows the pattern
of v8_enable_fast_mksnapshot and can improve build times by running an
optimized Torque compiler during debug builds. On my machine, this
change improves rebuild time after changing a .tq file by about 7
seconds.

Change-Id: I7c91d1059c614fe34eefe7ee8c3cba7c931d5a50
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1612160
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61556}

BUILD.gn

@@ -85,6 +85,9 @@ declare_args() {
   # Enable fast mksnapshot runs.
   v8_enable_fast_mksnapshot = false
 
+  # Optimize code for Torque executable, even during a debug build.
+  v8_enable_fast_torque = ""
+
   # Enable embedded builtins.
   v8_enable_embedded_builtins = true
 
@@ -228,6 +231,9 @@ if (v8_enable_snapshot_native_code_counters == "") {
 if (v8_enable_shared_ro_heap == "") {
   v8_enable_shared_ro_heap = v8_enable_lite_mode
 }
+if (v8_enable_fast_torque == "") {
+  v8_enable_fast_torque = v8_enable_fast_mksnapshot
+}
 
 assert(v8_current_cpu != "x86" || !v8_untrusted_code_mitigations,
        "Untrusted code mitigations are unsupported on ia32")
@@ -3371,6 +3377,12 @@ v8_source_set("torque_base") {
   if (is_win && is_asan) {
     remove_configs += [ "//build/config/sanitizers:default_sanitizer_flags" ]
   }
+
+  if (is_debug && !v8_optimized_debug && v8_enable_fast_torque) {
+    # The :no_optimize config is added to v8_add_configs in v8.gni.
+    remove_configs += [ "//build/config/compiler:no_optimize" ]
+    configs += [ ":always_optimize" ]
+  }
 }
 
 v8_source_set("torque_ls_base") {