Merge pull request #10718 from kernelmethod/libtcmalloc_fixes

# Try using TCMalloc on Linux

prepare_tcmalloc() {

    if [[ "${OSTYPE}" == "linux"* ]] && [[ -z "${NO_TCMALLOC}" ]] && [[ -z "${LD_PRELOAD}" ]]; then

        TCMALLOC="$(ldconfig -p | grep -Po "libtcmalloc.so.\d" | head -n 1)"

        TCMALLOC="$(PATH=/usr/sbin:$PATH ldconfig -p | grep -Po "libtcmalloc(_minimal|)\.so\.\d" | head -n 1)"

        if [[ ! -z "${TCMALLOC}" ]]; then

            echo "Using TCMalloc: ${TCMALLOC}"

            export LD_PRELOAD="${TCMALLOC}"