[mlir python] Change PyOpView constructor to construct operations. (#123777)
Previously ODS-generated Python operations had code like this:
```
super().__init__(self.build_generic(attributes=attributes, operands=operands, successors=_ods_successors, regions=regions, loc=loc, ip=ip))
```
we change it to:
```
super().__init__(self.OPERATION_NAME, self._ODS_REGIONS, self._ODS_OPERAND_SEGMENTS, self._ODS_RESULT_SEGMENTS, attributes=attributes, operands=operands, successors=_ods_successors, regions=regions, loc=loc, ip=ip)
```
This:
a) avoids an extra call dispatch (to `build_generic`), and
b) passes the class attributes directly to the constructor. Benchmarks
show that it is faster to pass these as arguments rather than having the
C++ code look up attributes on the class.
This PR improves the timing of the following benchmark on my workstation
from 5.3s to 4.5s:
```
def main(_):
with ir.Context(), ir.Location.unknown():
typ = ir.IntegerType.get_signless(32)
m = ir.Module.create()
with ir.InsertionPoint(m.body):
start = time.time()
for i in range(1000000):
arith.ConstantOp(typ, i)
end = time.time()
print(f"time: {end - start}")
```
Since this change adds an additional overload to the constructor and
does not alter any existing behaviors, it should be backwards
compatible.