[lldb][TypeSystem] Better support for _BitInt types (#165689)

Depends on:
* https://github.com/llvm/llvm-project/pull/165686

This patch ensures we make use of the `DW_AT_bit_size` on
`DW_TAG_base_type`s (which since
https://github.com/llvm/llvm-project/pull/164372 can exist on
`_BitInt`s) and adjusts `TypeSystemClang` to recognize `_BitInt`.

For DWARF from older versions of Clang that didn't emit a
`DW_AT_bit_size`, we would create `_BitInt`s using the byte-size. Not
sure we can do much better than that. But the situation beforehand
wasn't much better.

Before:
```
(lldb) v
(char) a = '\x01'
(unsigned char) b = '\x01'
(long) c = 2
(unsigned long) d = 2
```

After:
```
(lldb) v
(_BitInt(2)) a = 1
(unsigned _BitInt(2)) b = 1
(_BitInt(52)) c = 2
(unsigned _BitInt(52)) d = 2
```

Fixes https://github.com/llvm/llvm-project/issues/110273

0 files changed, 0 insertions, 0 deletions