[TF:XLA:INTERPRETER] speed up select and scatter by avoiding memory allocation in...

[TF:XLA:INTERPRETER] speed up select and scatter by avoiding memory allocation in loops

HandleSelectAndScatter() has 2 IterateThroughWindow() blocks. Before, we spent (in percent total program time):
11.98% Literal::CreateR0() = 10.82% (block1) + 1.16% (block2)
 4.91% Literal::~Literal() =  4.44% (block1) + 0.51% (block2)
 1.52% operator delete     =  1.38% (block1) + 0.14% (block2)
=====
18.41% total

After:
 1.99% Literal::~Literal() =  1.83% (block1) + 0.16% (block2)
 0.68% operator delete     =  0.61% (block1) + 0.07% (block2)
=====
 2.67% total
PiperOrigin-RevId: 196844177