[clang] [Sema] Add check for bitfield assignments to larger integral types (PR #68276)

[Aaron Ballman via cfe-commits]

================
@@ -185,6 +185,9 @@ New Compiler Flags
   the preprocessed text to the output. This can greatly reduce the size of the
   preprocessed output, which can be helpful when trying to reduce a test case.
 
+* ``-conversion-bitfield-assign`` was added to detect assignments of integral
----------------
AaronBallman wrote:

```suggestion
* ``-Wbitfield-conversion`` was added to detect assignments of integral
```

https://github.com/llvm/llvm-project/pull/68276