Merge `main` to `feature/flat_map`, update tests#6033

Merged

StephanTLavavej merged 11 commits intomicrosoft:feature/flat_mapfrom

StephanTLavavej:no-mister-bond-i-expect-you-to-merge

Jan 21, 2026

Commits on Jan 20, 2026

`<functional>`: unwrap `move_only_function` with abominable and noexcept types (#5917)

AlexGuteniev
and
StephanTLavavej
authored
Test that various Standard headers provide iterator range access functions (#5968)

vmichal
and
StephanTLavavej
authored
`<vector>`: Avoid off-by-default warning C4365 in `vector<bool>` copy algorithms with `/J` (#6013)
StephanTLavavej
authored
`STL.natvis`: Add visualizers for `ranges::less` and other comparison objects. (#6016)
vmichal
authored
`STL.natvis`: Improve iterator visualizations (#6019)
vmichal
authored
Add Neon implementation of `is_sorted_until` (#6018)
hazzlim
authored
`<cmath>`: Tolerate 80-bit `long double` (#6021)
statementreply
authored
`<regex>`: Optimize matching of branchless loops (#6022)

muellerj2
and
StephanTLavavej
authored
`<regex>`: Skip initial NFA nodes that do nothing during matching (#6026)
muellerj2
authored

Commits on Jan 21, 2026