zlib: do not emit event on *Sync() methods

WIP right now, still need to do it for more methods than just
gunzipSync().

Refs: nodejs#1668

lib/zlib.js

@@ -453,7 +453,9 @@ Zlib.prototype.flush = function(kind, callback) {
   }
 };
 
-Zlib.prototype.close = function(callback) {
+Zlib.prototype.close = function(callback, options) {
+  options = options || {};
+
   if (callback)
     process.nextTick(callback);
 
@@ -464,7 +466,9 @@ Zlib.prototype.close = function(callback) {
 
   this._handle.close();
 
-  process.nextTick(emitCloseNT, this);
+  if (!options.sync) {
+    process.nextTick(emitCloseNT, this);
+  }
 };
 
 function emitCloseNT(self) {
@@ -535,12 +539,12 @@ Zlib.prototype._processChunk = function(chunk, flushFlag, cb) {
     }
 
     if (nread >= kMaxLength) {
-      this.close();
+      this.close(null, {sync: true});
       throw new RangeError(kRangeErrorMessage);
     }
 
     var buf = Buffer.concat(buffers, nread);
-    this.close();
+    this.close(null, {sync: true});
 
     return buf;
   }