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.

This patch improves the GraphViz output of ViewOpGraph
(--view-op-graph).

- Switch to rectangular record-based nodes, inspired by a similar
visualization in [Glow](https://github.com/pytorch/glow). Rectangles
make more efficient use of space when printing text.
- Add input and output ports for each operand and result, and remove
edge labels.
- Switch to a muted color palette to reduce eye strain. 

Excluded updates to mlir/lib/AsmParser/Parser.cpp ,
which caused LIT failure "FAIL: MLIR::completion.test" on multiple buildbots.

This reverts commit 5a6e52d6ef96d2bcab6dc50bdb369662ff17d2a0.

"FAIL: MLIR::completion.test" on multiple buildbots.

* Strip calls to raw_string_ostream::flush(), which is essentially a no-op
* Strip unneeded calls to raw_string_ostream::str(), to avoid excess indirection.

PrintIRPass, PrintOpStatsPass and PrintOpGraphPass don't mutate IR so
preserve all analysis to save computation resource a bit.

This PR attempts to consolidate the different topological sort utilities
into one place. It adds them to the analysis folder because the
`SliceAnalysis` uses some of these.

There are now two different sorting strategies: 
1. Sort only according to SSA use-def chains
2. Sort while taking regions into account. This requires a much more
elaborate traversal and cannot be applied on graph regions that easily.

This additionally reimplements the region aware topological sorting
because the previous implementation had an exponential space complexity.

I'm open to suggestions on how to combine this further or how to fuse
the test passes.

Fixes #62128.