Use the `Base` type alias from https://github.com/llvm/llvm-project/pull/158433.

This patch adds support for lowering several float classification ops
from the Math dialect to the SPIR-V dialect.

### Highlights:
- Introduced a new `spirv.IsFinite` operation corresponding to the
SPIR-V `OpIsFinite` instruction.
- Lowered `math.isfinite`, `math.isinf`, and `math.isnan` to SPIR-V
using `CheckedElementwiseOpPattern`.
- Added corresponding tests for op definition and conversion lowering.

This addresses the discussion in:
https://github.com/llvm/llvm-project/issues/150778

---

Let me know if any additional adjustments are needed!

---------

Co-authored-by: Jakub Kuderski <kubakuderski@gmail.com>

See https://github.com/llvm/llvm-project/pull/147168 for more info.

These are identified by misc-include-cleaner.  I've filtered out those
that break builds.  Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.

Add Math to SPIRV lowering for tan, asin, acos, sinh, cosh, asinh, acosh
and atanh. This completes the lowering of all trigonometric and
hyperbolic functions from math to SPIRV.

The PR updates math.powf lowering to produce NaN result for a negative
base with a fractional exponent which matches the actual behaviour of
the C/C++ implementation.

This commit marks the type converter in `populate...` functions as
`const`. This is useful for debugging.

Patterns already take a `const` type converter. However, some
`populate...` functions do not only add new patterns, but also add
additional type conversion rules. That makes it difficult to find the
place where a type conversion was added in the code base. With this
change, all `populate...` functions that only populate pattern now have
a `const` type converter. Programmers can then conclude from the
function signature that these functions do not register any new type
conversion rules.

Also some minor cleanups around the 1:N dialect conversion
infrastructure, which did not always pass the type converter as a
`const` object internally.

As log2 and log10 are not available in spirv, realize them as a
decomposition using spirv.CL.log/spirv.GL.Log.

Add missing math.atan to spirv.CL.atan and math.atan2 to spirv.CL.atan2
in MathToSPIRV.
Add math.atan to spirv.GL.atan too.