[clang] [CIR] Upstream get_bitfield operation to load bit-field members from structs (PR #145971)

[Andy Kaylor via cfe-commits]

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@@ -76,3 +77,31 @@ void def() {
   T t;
   U u;
 }
+
+int load_field(S* s) {
+  return s->c;
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andykaylor wrote:

Can you add a test case with an unsigned field?

https://github.com/llvm/llvm-project/pull/145971