could and might

[zygoloid]

ISO wants us to avoid "could" and "might" appearing anywhere in the document. TODO list:

• Front matter + Clauses 1, 2, 3 -- no changes
• 4 General principles[intro] -- no changes
• 5 Lexical conventions[lex] -- jmaurer
• 6 Basics[basic] -- jmaurer
• 7 Expressions[expr] -- jmaurer
• 8 Statements[stmt.stmt] -- jmaurer
• 9 Declarations[dcl.dcl] -- jmaurer
• 10 Modules[module] -- no changes
• 11 Classes[class] -- jmaurer
• 12 Overloading[over] -- jmaurer
• 13 Templates[temp] -- jmaurer
• 14 Exception handling[except] -- jmaurer
• 15 Preprocessing directives[cpp] -- jmaurer
• 16 Library introduction[library] -- jmaurer
• 17 Language support library[support] -- jmaurer
• 18 Concepts library[concepts] -- jmaurer
• 19 Diagnostics library[diagnostics] -- jmaurer
• 20 General utilities library[utilities] -- jmaurer
• 21 Strings library[strings] -- jmaurer
• 22 Containers library[containers] -- jmaurer
• 23 Iterators library[iterators] -- jmaurer
• 24 Ranges library[ranges] -- jmaurer
• 25 Algorithms library[algorithms] -- jmaurer
• 26 Numerics library[numerics] -- jmaurer
• 27 Time library[time] -- jmaurer
• 28 Localization library[localization] -- jmaurer
• 29 Input/output library[input.output] -- jmaurer
• 30 Regular expressions library[re] -- jmaurer
• 31 Atomic operations library[atomics] -- jmaurer
• 32 Thread support library[thread] -- jmaurer
• Annex A (informative) Grammar summary[gram] -- no changes
• Annex B (informative normative) Implementation quantities[implimits] -- no changes
• Annex C (informative) Compatibility[diff] -- jmaurer
• Annex D (normative) Compatibility features -- jmaurer
• Back matter -- no changes

Please add your name next to a section to claim it, and check the box when it's done.

[JohelEGP]

Consider following @jensmaurer approach of using "possible" to replace "might", as shown in #4334, to maintain consistency.