The API of the {WasmGraphBuilder} should provide methods for all wasm
opcodes. For constants, that is {Int32Constant}, {Int64Constant},
{Float32Constant}, {Float64Constant}, and {Simd128Constant}. The other
helpers ({Uint32Constant} and {IntPtrConstant}) were only used
internally, hence remove them from the API and call the {MachineGraph}
method directly.

R=ahaas@chromium.org

Bug: v8:10933
Change-Id: Ifeec88f30062ede468bf6b7af2d2b214547130bc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2445475Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70333}