configure: suppress icc warnings
Every time a pointer to/from VALUE conversion happens, these two
warnings are issued:
- warning #1684: conversion from pointer to same-sized integral type (potential portability problem)
- warning #2312: pointer cast involving 64-bit pointed-to type
Thank you, but we are well aware of the "potential portability problem".
Let us ignore them all.
merge revision(s) 75802bcff1b941818832f0145071f7ce9c843d8d: