Do not suggest passing IFormatProvider to certain Convert methods

[CollinAlpert]

Affected analyzer: SpecifyIFormatProviderAnalyzer
Affected diagnostic ID: CA1305

This PR prevents suggesting to pass an IFormatProvider to Convert.ToX methods where passing an IFormatProvider would change nothing.

Fixes #7154

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.49%. Comparing base (68eda2d) to head (65a0697).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff            @@
##             main    #7244    +/-   ##
========================================
  Coverage   96.49%   96.49%            
========================================
  Files        1443     1443            
  Lines      345972   346376   +404     
  Branches    11383    11387     +4     
========================================
+ Hits       333856   334252   +396     
- Misses       9235     9242     +7     
- Partials     2881     2882     +1     

[buyaa-n]

Got some NITs:

• Better to check null before head to avoid null check each reference and creating empty array
• For ToChar, ToBoolean we expect only one method to get, no need to create array for this
• m.IsStatic is redundant as Convert is a static type, all methods are static anyways
  Something like:

Suggested change

	var superfluousConvertToStringFormatProviderOverloads = convertType?.GetMembers(nameof(Convert.ToString))
	.OfType<IMethodSymbol>()
	.Where(m => m.IsStatic
	&& m.Parameters is [{ Type.SpecialType: SpecialType.System_String or SpecialType.System_Boolean or SpecialType.System_Char }, var possibleFormatProvider]
	&& possibleFormatProvider.Type.Equals(iformatProviderType, SymbolEqualityComparer.Default)) ?? [];
	var superfluousConvertToToCharFormatProviderOverloads = convertType?.GetMembers(nameof(Convert.ToChar))
	.OfType<IMethodSymbol>()
	.Where(m => m.IsStatic
	&& m.Parameters is [{ Type.SpecialType: SpecialType.System_String }, var possibleFormatProvider]
	&& possibleFormatProvider.Type.Equals(iformatProviderType, SymbolEqualityComparer.Default)) ?? [];
	var superfluousConvertToBooleanFormatProviderOverloads = convertType?.GetMembers(nameof(Convert.ToBoolean))
	.OfType<IMethodSymbol>()
	.Where(m => m.IsStatic
	&& m.Parameters is [{ Type.SpecialType: SpecialType.System_String }, var possibleFormatProvider]
	&& possibleFormatProvider.Type.Equals(iformatProviderType, SymbolEqualityComparer.Default)) ?? [];
	ImmutableHashSet<IMethodSymbol> superfluousFormatProviderOverloads = superfluousConvertToStringFormatProviderOverloads
	.Concat(superfluousConvertToToCharFormatProviderOverloads)
	.Concat(superfluousConvertToBooleanFormatProviderOverloads)
	.ToImmutableHashSet<IMethodSymbol>(SymbolEqualityComparer.Default);
	ImmutableHashSet<IMethodSymbol> superfluousFormatProviderOverloads = ImmutableHashSet<IMethodSymbol>.Empty;
	if (convertType != null)
	{
	superfluousFormatProviderOverloads = convertType.GetMembers(nameof(Convert.ToString))
	.OfType<IMethodSymbol>()
	.Where(m => m.Parameters is [{ Type.SpecialType: SpecialType.System_String or SpecialType.System_Boolean or SpecialType.System_Char }, var possibleFormatProvider]
	&& possibleFormatProvider.Type.Equals(iformatProviderType, SymbolEqualityComparer.Default)).ToImmutableHashSet();
	superfluousFormatProviderOverloads = superfluousFormatProviderOverloads
	.Add(convertType.GetMembers(nameof(Convert.ToChar))
	.OfType<IMethodSymbol>()
	.First(m => m.Parameters is [{ Type.SpecialType: SpecialType.System_String }, var possibleFormatProvider]
	&& possibleFormatProvider.Type.Equals(iformatProviderType, SymbolEqualityComparer.Default)))
	.Add(convertType.GetMembers(nameof(Convert.ToBoolean))
	.OfType<IMethodSymbol>()
	.First(m => m.Parameters is [{ Type.SpecialType: SpecialType.System_String }, var possibleFormatProvider]
	&& possibleFormatProvider.Type.Equals(iformatProviderType, SymbolEqualityComparer.Default)));
	}

[CollinAlpert]

Thanks for the review!

[buyaa-n]

Overall LGTM, thanks @CollinAlpert

[buyaa-n]

Thank you!