PS the squeals you are talking about in the trade off at the end of Cemetery Gates are definitely NOT pinch harmonics, they are plain harmonics with a good tremelo. Try it and see, you will never get that high with a pinched harmonic because the strings will touch the fret board before the level is achieve. The reason being, the higher up the fret board you go, the shorter the distance between the string and the last fret (22 or 24 depending on your guitar). A regular harmonic gives you a few extra precious millimetres to play with when bending the arm back, try it and you will see that there is no comparison.
Q.E.D!
;-)

PPS Pinched harmonics are used on the heavy riff at the begining on the last two notes of notes of each bar.