None

These questions don't seem to be particularly useful for designing/implementing programming languages yourself. The answers to them may be interesting when accompanied by more information about why those languages have <XYZ>, but if answers only include a list of languages with the given feature, they're not particularly helpful to anyone but the question asker. I'd treat them similarly to questions asking for tutorials and other off-site resources.

They can, however, be turned into more useful questions. For example, maybe the first question could be turned into "How to include source locations when compiling to Lua bytecode?", which would be useful to someone who is making a language that targets Lua bytecode and wants their error messages to be helpful.

None

These questions don't seem to be particularly useful for designing/implementing programming languages yourself. The answers to them may be interesting when accompanied by more information about why those languages have <XYZ>, but if answers only include a list of languages with the given feature, they're not particularly helpful to anyone but the question asker. I'd treat them similarly to questions asking for tutorials and other off-site resources.

They can, however, be turned into more useful questions by making them about why a language would do <XYZ> rather than which languages do <XYZ>. For example, the second question could be turned into something like "Why would a language provide arrays whose lengths are always a power of two?"

Such questions can also be made on-topic by making them about how a language would implement <XYZ>. For example, the first question could be turned into "How to include source locations when compiling to Lua bytecode?", which would be useful to someone who is making a language that targets Lua bytecode and wants their error messages to be helpful.

None

These questions don't seem to be particularly useful for designing/implementing programming languages yourself. The answers to them may be interesting when accompanied by more information about why those languages have , but if answers only include a list of languages with the given feature, they're not particularly helpful to anyone but the question asker. I'd treat them similarly to questions asking for tutorials and other off-site resources.

They can, however, be turned into more useful questions. For example, maybe the first question could be turned into "How to include source locations when compiling to Lua bytecode?", which would be useful to someone who is making a language that targets Lua bytecode and wants their error messages to be helpful.

None

These questions don't seem to be particularly useful for designing/implementing programming languages yourself. The answers to them may be interesting when accompanied by more information about why those languages have <XYZ>, but if answers only include a list of languages with the given feature, they're not particularly helpful to anyone but the question asker. I'd treat them similarly to questions asking for tutorials and other off-site resources.

They can, however, be turned into more useful questions. For example, maybe the first question could be turned into "How to include source locations when compiling to Lua bytecode?", which would be useful to someone who is making a language that targets Lua bytecode and wants their error messages to be helpful.