add checks to avoid potential buffer overflows and prevent exceptions

number_platform_modes variable is from another module (e.g.,
eModule->get_number_of_platform_modes(mModule)) and thus can be
a big number. If a big number is used as the size of new operation,
it can cause an exception as is.

Test: mma
Change-Id: I6cf6027804be980ad39c80a1571b284efabce7e8