Use CT_DoExecLog for MPFR build.

/trunk/scripts/build/mpfr.sh | 48 25 23 0 +++++++++++++++++++++++++-----------------------
1 file changed, 25 insertions(+), 23 deletions(-)

# Compute x86_64-specific values

CT_DoArchValues() {

    # The architecture part of the tuple:

    CT_TARGET_ARCH="${CT_ARCH}"

}