This patch adds a new `FramePointerKind::NonLeafNoReserve` and makes it
the default for `-momit-leaf-frame-pointer`.

It also adds a new commandline option `-m[no-]reserve-frame-pointer-reg`.

This should fix #154379, the main impact of this patch can be found in
`clang/lib/Driver/ToolChains/CommonArgs.cpp`.

Update `.Cases` and `.CasesLower` with 4+ args to use the
`initializer_list` overload. The deprecation of these functions will
come in a separate PR.

For more context, see: https://github.com/llvm/llvm-project/pull/163405.

Remove `UnsafeFPMath` uses, next is removing the command line option.

Same as 07a86a525ea2f85ade9e224c200f0311fec9e433, except in
ther other case here.

Instead of pre-checking if the frame-pointer attribute is present,
just query the attribute and see if it's valid.

The -mno-omit-leaf-frame-pointer flag works on 32-bit ARM architectures
and addresses the bug reported in #108019

When using the -mframe-chain=aapcs or -mframe-chain=aapcs-leaf options,
we cannot use r11 as an allocatable register, even if
-fomit-frame-pointer is also used. This is so that r11 will always point
to a valid frame record, even if we don't create one in every function.

This is a (fixed) recommit of https://reviews.llvm.org/D121169

after:  1061034926
before: 1063332844

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D121681

This reverts commit 7f230feeeac8a67b335f52bd2e900a05c6098f20.
Breaks CodeGenCUDA/link-device-bitcode.cu in check-clang,
and many LLVM tests, see comments on https://reviews.llvm.org/D121169

after:  1061034926
before: 1063332844

Differential Revision: https://reviews.llvm.org/D121169