Rollup of 7 pull requests

[JonathanBrouwer]

Successful merges:

• Use allocator_shim_contents in allocator_shim_symbols #149848 (Use allocator_shim_contents in allocator_shim_symbols)
• Add Tier 3 Thumb-mode targets for Armv7-A, Armv7-R and Armv8-R #150556 (Add Tier 3 Thumb-mode targets for Armv7-A, Armv7-R and Armv8-R)
• Fix is_ascii performance regression on AVX-512 CPUs when compiling with -C target-cpu=native #151259 (Fix is_ascii performance regression on AVX-512 CPUs when compiling with -C target-cpu=native)
• Add "Skip to main content" link for keyboard navigation in rustdoc #151482 (Add "Skip to main content" link for keyboard navigation in rustdoc)
• Various refactors to the proc_macro bridge #151505 (Various refactors to the proc_macro bridge)
• Enable reproducible binary builds with debuginfo on Linux #151517 (Enable reproducible binary builds with debuginfo on Linux)
• Tweak bounds check in DepNodeColorMap.get #151540 (Tweak bounds check in DepNodeColorMap.get)

r? @ghost

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