[metadata] Don't access MonoTableInfo:rows, use table_info_get_rows()

[lambdageek]

Rename the field to rows_.

Also updated some bounds checks to use mono_metadata_table_bounds_check (which
is metadata-update aware) where the subsequent lookups go through the metadata
decode functions and should just work with metadata-update.

Added FIXME: metadata-update in cases where the table row size is assumed to be
fixed or is used as a sentinel value, or where the decoding may depend on
sorting properties that metadata updates probably won't uphold.

Contributes to #44806

[ghost]

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Issue Details

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Rename the field to rows_.

Also updated some bounds checks to use mono_metadata_table_bounds_check (which
is metadata-update aware) where the subsequent lookups go through the metadata
decode functions and should just work with metadata-update.

Added FIXME: metadata-update in cases where the table row size is assumed to be
fixed or is used as a sentinel value, or where the decoding may depend on
sorting properties that metadata updates probably won't uphold.

Contributes to #44806

Author:	lambdageek
Assignees:	-
Labels:	area-VM-meta-mono
Milestone:	-

[CoffeeFlux]

Think you need to rebase this.

[marek-safar]

@vargaz could you please review the change?

[thaystg]

LGTM.

[uweigand]

Hi @lambdageek, I think this patch introduced a regression here https://github.com/dotnet/runtime/pull/49738/files#diff-9bd9d0e46241d07dc62110246c89c9f056333eff4b0b089551780a625c871d0dL1982:

This used to set param_last to the number of rows of the PARAMS table, but now it sets it to the number of rows in the METHOD table, which looks incorrect, and does in fact cause assertion failures in the roslyn test suite for me:

* Assertion at /home/vol2/runtimelab/src/mono/mono/metadata/metadata.c:1535, condition `idx < table_info_get_rows (t)' not met

[lambdageek]

Thanks @uweigand!