s390: [csa][builtin] Port ArrayConstructor builtin to CSA.

Port 7745c73a

R=ishell@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: I34a7bda297486455ad3d809f2def490113bcf15c
Reviewed-on: https://chromium-review.googlesource.com/1099640Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#53720}

src/builtins/s390/builtins-s390.cc

@@ -83,12 +83,6 @@ void Builtins::Generate_AdaptorWithBuiltinExitFrame(MacroAssembler* masm) {
   AdaptorWithExitFrameType(masm, BUILTIN_EXIT);
 }
 
-// Load the built-in Array function from the current context.
-static void GenerateLoadArrayFunction(MacroAssembler* masm, Register result) {
-  // Load the Array function from the current native context.
-  __ LoadNativeContextSlot(Context::ARRAY_FUNCTION_INDEX, result);
-}
-
 void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r2     : number of arguments