Rollup of 10 pull requests

[samueltardieu]

Successful merges:

• wrapping shift: remove first bitmask and table #143355 (wrapping shift: remove first bitmask and table)
• remote-test-client: Exit code 128 + <signal-number> instead of 3 #143448 (remote-test-client: Exit code 128 + <signal-number> instead of 3)
• miri: fix out-of-bounds error for ptrs with negative offsets #143692 (miri: fix out-of-bounds error for ptrs with negative offsets)
• Emit warning when there is no space between -o and arg #143719 (Emit warning when there is no space between -o and arg)
• Move several float tests to floats/mod.rs #143738 (Move several float tests to floats/mod.rs)
• Port #[coverage] to the new attribute system #143891 (Port #[coverage] to the new attribute system)
• Make more of codegen_llvm safe #143920 (Make more of codegen_llvm safe)
• Constify Index traits #143921 (Constify Index traits)
• Update mdbook to 0.4.52 #143948 (Update mdbook to 0.4.52)
• Add tracing to InterpCx::fn_abi_of_instance/fn_abi_of_fn_ptr #143968 (Add tracing to InterpCx::fn_abi_of_instance/fn_abi_of_fn_ptr)

r? @ghost
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