Generalize optimizer step profiler

[cameel]

This PR moves the simple profiling setup we had in Suite.cpp and moves it into a separate class that can be easily used in random places.

It also switches to static storage for the metrics, which means that we get a single report with total running time over all the Yul objects rather than one per object. Originally the profiler was used with small contracts from test/benchmarks/ where it was probably manageable, but when profiling big projects like Uniswap or OpenZeppelin, the aggregate data is much more useful.

Using the profiler is now as easy as dropping a PROFILER_PROBE() macro in the scope that is meant to be measured. The default probes are still placed only around the optimizer steps, but new ones can be added ad-hoc, locally.

The PR also tweaks the output to make it easy to post it in comments in a readable form. It also tracks the number of calls in addition to the timing.

[cameel]

Here's what the output looks like when profiling a simple empty contract.

Before

Performance metrics of optimizer steps
======================================
  0.000% (0 s): VarDeclInitializer
  0.000% (0 s): ForLoopConditionOutOfBody
  0.098% (1e-06 s): SSAReverser
  0.098% (1e-06 s): Rematerialiser
  0.098% (1e-06 s): ExpressionInliner
  0.197% (2e-06 s): UnusedFunctionParameterPruner
  0.197% (2e-06 s): FunctionSpecializer
  0.295% (3e-06 s): ExpressionJoiner
  0.295% (3e-06 s): ForLoopConditionIntoBody
  0.394% (4e-06 s): CircularReferencesPruner
  0.394% (4e-06 s): StructuralSimplifier
  0.394% (4e-06 s): ForLoopInitRewriter
  0.394% (4e-06 s): BlockFlattener
  0.394% (4e-06 s): ControlFlowSimplifier
  0.492% (5e-06 s): ConditionalSimplifier
  0.492% (5e-06 s): FunctionGrouper
  0.689% (7e-06 s): ConditionalUnsimplifier
  0.689% (7e-06 s): FunctionHoister
  0.984% (1e-05 s): SSATransform
  1.083% (1.1e-05 s): LoopInvariantCodeMotion
  1.083% (1.1e-05 s): LiteralRematerialiser
  1.083% (1.1e-05 s): EqualStoreEliminator
  1.575% (1.6e-05 s): EquivalentFunctionCombiner
  1.673% (1.7e-05 s): ExpressionSplitter
  1.969% (2e-05 s): FullInliner
  2.264% (2.3e-05 s): UnusedStoreEliminator
  2.461% (2.5e-05 s): DeadCodeEliminator
  2.657% (2.7e-05 s): LoadResolver
  2.756% (2.8e-05 s): UnusedAssignEliminator
  3.937% (4e-05 s): UnusedPruner
  6.004% (6.1e-05 s): CommonSubexpressionEliminator
 64.862% (0.000659 s): ExpressionSimplifier
--------------------------------------
    100% (0.001 s)
Performance metrics of optimizer steps
======================================
  0.000% (0 s): BlockFlattener
  0.000% (0 s): StructuralSimplifier
  0.000% (0 s): ControlFlowSimplifier
  0.000% (0 s): ForLoopConditionIntoBody
  0.000% (0 s): ForLoopConditionOutOfBody
  0.000% (0 s): ForLoopInitRewriter
  0.131% (1e-06 s): VarDeclInitializer
  0.131% (1e-06 s): FunctionGrouper
  0.262% (2e-06 s): UnusedFunctionParameterPruner
  0.262% (2e-06 s): SSAReverser
  0.262% (2e-06 s): FunctionHoister
  0.394% (3e-06 s): ExpressionInliner
  0.525% (4e-06 s): FunctionSpecializer
  0.919% (7e-06 s): ExpressionJoiner
  1.181% (9e-06 s): CircularReferencesPruner
  1.181% (9e-06 s): Rematerialiser
  1.706% (1.3e-05 s): SSATransform
  1.837% (1.4e-05 s): EquivalentFunctionCombiner
  3.018% (2.3e-05 s): ConditionalSimplifier
  3.150% (2.4e-05 s): EqualStoreEliminator
  3.543% (2.7e-05 s): DeadCodeEliminator
  3.543% (2.7e-05 s): ConditionalUnsimplifier
  3.806% (2.9e-05 s): ExpressionSplitter
  4.068% (3.1e-05 s): LoopInvariantCodeMotion
  4.199% (3.2e-05 s): UnusedStoreEliminator
  4.462% (3.4e-05 s): FullInliner
  5.774% (4.4e-05 s): LiteralRematerialiser
  6.168% (4.7e-05 s): ExpressionSimplifier
  6.430% (4.9e-05 s): LoadResolver
  6.955% (5.3e-05 s): UnusedAssignEliminator
 14.436% (0.00011 s): UnusedPruner
 21.654% (0.000165 s): CommonSubexpressionEliminator
--------------------------------------
    100% (0.001 s)

After

PERFORMANCE METRICS FOR PROFILED SCOPES

| Time % | Time       | Calls   | Scope                          |
|-------:|-----------:|--------:|--------------------------------|
|   0.0% |    0.000 s |      10 | ForLoopConditionOutOfBody      |
|   0.0% |    0.000 s |       4 | ForLoopInitRewriter            |
|   0.2% |    0.000 s |      20 | BlockFlattener                 |
|   0.2% |    0.000 s |       4 | SSAReverser                    |
|   0.2% |    0.000 s |       6 | ForLoopConditionIntoBody       |
|   0.2% |    0.000 s |       2 | UnusedFunctionParameterPruner  |
|   0.2% |    0.000 s |      11 | StructuralSimplifier           |
|   0.2% |    0.000 s |       2 | ExpressionInliner              |
|   0.3% |    0.000 s |       2 | VarDeclInitializer             |
|   0.3% |    0.000 s |      12 | ControlFlowSimplifier          |
|   0.3% |    0.000 s |       2 | FunctionSpecializer            |
|   0.4% |    0.000 s |      14 | FunctionGrouper                |
|   0.5% |    0.000 s |       8 | ExpressionJoiner               |
|   0.5% |    0.000 s |       6 | Rematerialiser                 |
|   0.5% |    0.000 s |       4 | FunctionHoister                |
|   0.7% |    0.000 s |      18 | CircularReferencesPruner       |
|   1.6% |    0.000 s |       7 | ConditionalSimplifier          |
|   1.8% |    0.000 s |       8 | EquivalentFunctionCombiner     |
|   1.9% |    0.000 s |       9 | ConditionalUnsimplifier        |
|   2.1% |    0.000 s |       2 | EqualStoreEliminator           |
|   2.5% |    0.000 s |       8 | LoopInvariantCodeMotion        |
|   2.5% |    0.000 s |       8 | SSATransform                   |
|   2.7% |    0.000 s |       6 | ExpressionSplitter             |
|   3.0% |    0.000 s |       8 | DeadCodeEliminator             |
|   3.3% |    0.000 s |       6 | FullInliner                    |
|   3.3% |    0.000 s |       2 | UnusedStoreEliminator          |
|   4.1% |    0.000 s |      19 | LiteralRematerialiser          |
|   4.9% |    0.000 s |      10 | UnusedAssignEliminator         |
|   5.9% |    0.000 s |       6 | LoadResolver                   |
|   9.0% |    0.000 s |      20 | UnusedPruner                   |
|  14.7% |    0.000 s |      23 | CommonSubexpressionEliminator  |
|  32.2% |    0.001 s |       9 | ExpressionSimplifier           |
| 100.0% |    0.002 s |     276 | **TOTAL**                      |

[cameel]

So, as can be seen in run 36438, the code does compile on all platforms.

The three CLI test jobs fail, but that was already the case before due to the extra output that the profiler prints unconditionally. Perhaps we should add a proper flag for it, but in this PR I'm just leaving it as is.