Perf: speed up _zsh_highlight_main_add_region_highlight

Author: romkatv

highlighters/main/main-highlighter.zsh

@@ -73,29 +73,20 @@ _zsh_highlight_highlighter_main_predicate()
 
 # Helper to deal with tokens crossing line boundaries.
 _zsh_highlight_main_add_region_highlight() {
-  integer start=$1 end=$2
-  shift 2
-
   if (( in_alias )); then
-    [[ $1 == unknown-token ]] && alias_style=unknown-token
+    [[ $3 == unknown-token ]] && alias_style=unknown-token
     return
   fi
+
   if (( in_param )); then
-    if [[ $1 == unknown-token ]]; then
-      param_style=unknown-token
+    if [[ -z $param_style || $3 == unknown-token ]]; then
+      param_style=$3
     fi
-    if [[ -n $param_style ]]; then
-      return
-    fi
-    param_style=$1
     return
   fi
 
   # The calculation was relative to $buf but region_highlight is relative to $BUFFER.
-  (( start += buf_offset ))
-  (( end += buf_offset ))
-
-  list_highlights+=($start $end $1)
+  list_highlights+=($(( $1 + buf_offset )) $(( $2 + buf_offset )) $3)
 }
 
 _zsh_highlight_main_add_many_region_highlights() {