Fix various named enum types

[jakebailey]

Noticed these while trying gosec. Most of these are enum types that are paired up with another but underlying types differed, which is weird.

regexp2's constants are broken; they mistakenly forgot that only iota keeps inferring the same type as the first "enum" value in a block.

[Copilot]

Pull Request Overview

This PR updates type definitions for several flag enums from signed to unsigned integers for better semantic correctness, and refactors regex pattern compilation in VFS utilities.

• Changes flag types from int32 to uint32 where values represent bitfields
• Changes JSDocParsingMode from int to uint8 for a small enum with 4 values
• Refactors GetRegexFromPattern to declare options variable upfront and build it conditionally
• Updates fuzz tests to use correct primitive types (int32 and uint8) matching the underlying enum types
• Updates module resolver test to use proper core.ModuleKind type instead of int

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
internal/vfs/utilities.go	Refactored regex options initialization to declare variable first, then conditionally modify it
internal/parser/testdata/fuzz/FuzzParser/9ce2d994c65c7bfe	Updated fuzz test corpus to use int32 and uint8 types
internal/parser/testdata/fuzz/FuzzParser/02b74efe61495c2a	Updated fuzz test corpus to use int32 and uint8 types
internal/parser/parser_test.go	Updated fuzz test to use int32 for ScriptTarget and uint8 for JSDocParsingMode
internal/nodebuilder/types.go	Changed Flags type from int32 to uint32 for bitfield operations
internal/module/resolver_test.go	Changed ResolutionMode from int to core.ModuleKind and removed unnecessary type casts
internal/checker/types.go	Changed SymbolFormatFlags from int32 to uint32 for bitfield operations
internal/ast/subtreefacts.go	Changed SubtreeFacts from int32 to uint32 for bitfield operations
internal/ast/parseoptions.go	Changed JSDocParsingMode from int to uint8 for small enum

Comments suppressed due to low confidence (1)

internal/parser/parser_test.go:130

• The upper bound check is incorrect. JSDocParsingModeParseNone has value 1 (second in iota sequence), but the last value is JSDocParsingModeParseForTypeInfo which has value 3. The condition should be jsdocParsingMode > ast.JSDocParsingModeParseForTypeInfo to correctly validate the full range of valid enum values (0-3).

		if jsdocParsingMode < ast.JSDocParsingModeParseAll || jsdocParsingMode > ast.JSDocParsingModeParseNone {