JIT: some small profile related fixes (#43408)

JIT: some small profile related fixes (#43408)

1. If we're inheriting a fraction of the profile weight of a profiled block,
mark the inheriting block as profiled. This prevents methods like
`optSetBlockWeights` or `optMarkLoopBlocks` from coming along later and setting
the weights to something else. Since the full inheritance method has similar
logic, make it delegate to the fractional one, with a scale of 100 (no scaling).

2. If we switch from Tier0 to FullOpt, make sure to clear the BBINSTR flag,
else we'll put probes into optimized code.

3. Dump edge weights in the dot graph, if we have them.

4. Only dump the flow graph twice per phase.