Tiny optimization for complier templates for arm.

1. Remove possible bubble in TEMPLATE_STRING_INDEXOF.S
2. Remove 1 instruction and reorder the opcodes
   TEMPLATE_MUL_LONG.S
3. Reorder ldr r2 instruction in TEMPLATE_RETURN.S

Change-Id: I571c1278aa72cb1e6dbc6efe433932d5e9591b80