[ffi] AbiSpecificIntegerArray explicit type argument

This makes it explicit on the call site what the integer is,
simplifying follow up CLs.

TEST=tests/ffi

CoreLibraryReviewExempt: implementation change only.
Bug: #54739
Change-Id: Ib5bc09f4194e9103cf42eb3851b2308553fd8990
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/360640
Commit-Queue: Daco Harkes <[email protected]>
Reviewed-by: Tess Strickland <[email protected]>

Author: dcharkes

sdk/lib/_internal/vm/lib/ffi_patch.dart

@@ -1380,7 +1380,7 @@ extension UnionArray<T extends Union> on Array<T> {
 }
 
 @patch
-extension AbiSpecificIntegerArray on Array<AbiSpecificInteger> {
+extension AbiSpecificIntegerArray<T extends AbiSpecificInteger> on Array<T> {
   @patch
   int operator [](int index) {
     throw ArgumentError(

sdk/lib/ffi/ffi.dart

@@ -1465,7 +1465,7 @@ extension ArrayArray<T extends NativeType> on Array<Array<T>> {
 
 /// Bounds checking indexing methods on [Array]s of [AbiSpecificInteger].
 @Since('2.16')
-extension AbiSpecificIntegerArray on Array<AbiSpecificInteger> {
+extension AbiSpecificIntegerArray<T extends AbiSpecificInteger> on Array<T> {
   external int operator [](int index);
 
   external void operator []=(int index, int value);