Use CCNOT instead of AND for multi-controlled operations (#2807)

This avoids the measurement-based uncomputation in the intrinsic `AND`
operation in favor of just using `CCNOT` when decomposing multiple
controls on `Std.Intrinsic` gates. This leaves optimization of resulting
QIR ccx to the program author or the backend that receives the QIR. This
makes the behavior of most code more predictable and straightforward,
and avoids special (often expensive) adaptive behavior being triggered
automatically/enexpectedly by use of multi-controlled gates.
Other libraries still use the existing `AND` with it's alternate
approach, such as the arithmetic libraries, which keeps the behavior and
resource estimates of those more advanced programs largely the same.

Author: swernli

library/std/src/Std/InternalHelpers.qs

@@ -109,21 +109,21 @@ internal operation EntangleForJointMeasure(basis : Pauli, aux : Qubit, qubit : Q
 internal operation CollectControls(ctls : Qubit[], aux : Qubit[], adjustment : Int) : Unit is Adj {
     // First collect the controls into the first part of the auxiliary list.
     for i in 0..2..(Length(ctls) - 2) {
-        AND(ctls[i], ctls[i + 1], aux[i / 2]);
+        CCNOT(ctls[i], ctls[i + 1], aux[i / 2]);
     }
     // Then collect the auxiliary qubits in the first part of the list forward into the last
     // qubit of the auxiliary list. The adjustment is used to allow the caller to reduce or increase
     // the number of times this is run based on the eventual number of control qubits needed.
     for i in 0..((Length(ctls) / 2) - 2 - adjustment) {
-        AND(aux[i * 2], aux[(i * 2) + 1], aux[i + Length(ctls) / 2]);
+        CCNOT(aux[i * 2], aux[(i * 2) + 1], aux[i + Length(ctls) / 2]);
     }
 }
 
 /// When collecting controls, if there is an uneven number of original control qubits then the
 /// last control and the second to last auxiliary will be collected into the last auxiliary.
 internal operation AdjustForSingleControl(ctls : Qubit[], aux : Qubit[]) : Unit is Adj {
     if Length(ctls) % 2 != 0 {
-        AND(ctls[Length(ctls) - 1], aux[Length(ctls) - 3], aux[Length(ctls) - 2]);
+        CCNOT(ctls[Length(ctls) - 1], aux[Length(ctls) - 3], aux[Length(ctls) - 2]);
     }
 }