Fix compilation failure on big-endian

Fix 0caf1d20

Bug: 
Change-Id: I275417e8236ef0ee2cc6fef188585b0b786d8a05
Reviewed-on: https://chromium-review.googlesource.com/602268Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Cr-Commit-Position: refs/heads/master@{#47167}

src/builtins/builtins-string-gen.cc

@@ -1791,7 +1791,7 @@ TNode<Uint32T> StringBuiltinsAssembler::LoadSurrogatePairAt(
         var_result = Unsigned(Word32Or(
 // Need to swap the order for big-endian platforms
 #if V8_TARGET_BIG_ENDIAN
-            Word32Shl(lead, Int32Constant(16)), trail);
+            Word32Shl(lead, Int32Constant(16)), trail));
 #else
             Word32Shl(trail, Int32Constant(16)), lead));
 #endif