[clang] [CIR][ABI] Add _BitInt flag to IntType (PR #188113)

[Andy Kaylor via cfe-commits]

================
@@ -53,10 +53,10 @@ char32_t c32;
 // CHECK: cir.global external @c32 = #cir.int<0> : !u32i
 
 _BitInt(20) sb20;
-// CHECK: cir.global external @sb20 = #cir.int<0> : !cir.int<s, 20>
+// CHECK: cir.global external @sb20 = #cir.int<0> : !cir.int<s, 20, bitint>
----------------
andykaylor wrote:

Can you add a `_BitInt(128)` and check the alignment? It should get different alignment than `__int128` (see https://godbolt.org/z/b46eGY4s8). You may need to make another change somewhere to handle that correctly.

https://github.com/llvm/llvm-project/pull/188113