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

[Erich Keane via cfe-commits]

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@@ -6171,6 +6171,9 @@ def warn_signed_bitfield_enum_conversion : Warning<
   "signed bit-field %0 needs an extra bit to represent the largest positive "
   "enumerators of %1">,
   InGroup<BitFieldEnumConversion>, DefaultIgnore;
+def warn_bitfield_too_small_for_integral_type : Warning<
+  "bit-field %0 (%1 bits) is not wide enough to store type of %2 ">,
+  InGroup<Conversion>, DefaultIgnore;
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erichkeane wrote:

While I think this SHOULD be in `-Wconversion`,  I think it should be a sub-group of it, so that it can be disabled separately.  This is a warning that could likely end up with false positives, and should separately be disable-able.

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