[clang-c] introduce queries on GCC-style inline assembly statements (#143424)
[Discourse
link](https://discourse.llvm.org/t/a-small-proposal-for-extraction-of-inline-assembly-block-information/86658)
We strive for exposing such information using existing stable ABIs. In
doing so, queries are limited to what the original source holds or the
LLVM IR `asm` block would expose in connection with attributes that the
queries are concerned.
These APIs opens new opportunities for `rust-bindgen` to translate
inline assemblies in reasonably cases into Rust inline assembly blocks,
which would further aid better interoperability with other existing
code.
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Signed-off-by: Xiangfei Ding <dingxiangfei2009@protonmail.ch>