If the broadcast is already the full vector width, try to prefer a blend over a vector insertion which is usually a lower latency (and sometimes a lower uop count).

All uses have been replaced by GetAddressRange*s* or GetAddress.

Also fix two internal uses of the range member.

The surrounding code doesn't use them anymore. This removes the internal
usages.

This patch makes the Rows actual values. An alternative would be to make
them unique_ptrs. That would make vector resizes faster at the cost of
more pointer chasing and heap fragmentation. I don't know which one is
better so I picked the simpler option.

This parallels the GNU Binutils feature's usage. A hidden command-line
option `--loongarch-no-aliases` is also added, similar to how
`--loongarch-numeric-reg` is for the `numeric` option.

It was excluded from spilling in a263a60, possibly by accident.

In the linked bug, we hit a situation like this:

```
  %s = call @llvm.coro.suspend(...)
             |
       switch (%s)
case v1: /       \ case v2:
        ...      ...
         |       suspend point
         |       ...
         \       /
 %x = phi [v1] [v2]
             |
            ...
             |
         use(%x)
```

Instcombine will notice that %x correlates exactly with %s, and so
use(%x) becomes use(%s).

However, corosplit would substitute different values for %s when
splitting the function, so even though %s had a particular value when
control actually passed through the switch, it could have a *different*
value when reaching use(%s).

This illustrates that while IR from the frontend typically does not use
these suspend return values across suspend points, mid-level
optimizations on the presplit coroutine may introduce new uses of
suspend values, so they must be considered eligible to spill to the
coroutine frame.

Fixes: #130326

These four functions all related in that they share tables and helper
functions. Furthermore, the acosh and atanh builtins call log1p.

As with other work in this area, these builtins are now vectorized. To
enable this, there are new table accessor functions which return a
vector of table values using a vector of indices. These are internally
scalarized, in the absence of gather operations. Some tables which were
tables of multiple entries (e.g., double2) are split into two separate
"low" and "high" tables. This might affect the performance of memory
operations but are hopefully mitigated by better codegen overall.