Merge commit '6204bb245b4a05e0f4f00bb48d83b76ebcd899e2' into zig0-0.15.2

stage0/astgen_test.zig

@@ -325,6 +325,11 @@ fn expectEqualData(
                 .shl_with_overflow,
                 .restore_err_ret_index,
                 .branch_hint,
+                // Container decl Small packed structs have undefined padding bits.
+                .struct_decl,
+                .enum_decl,
+                .union_decl,
+                .opaque_decl,
                 => true,
                 else => false,
             };

stage0/zir.h

@@ -513,6 +513,23 @@ typedef union {
 #define ZIR_REF_BOOL_FALSE 122
 #define ZIR_REF_EMPTY_TUPLE 123
 
+// Zir.Inst.BuiltinValue enum (Zir.zig:3476-3494).
+#define ZIR_BUILTIN_VALUE_ATOMIC_ORDER 0
+#define ZIR_BUILTIN_VALUE_ATOMIC_RMW_OP 1
+#define ZIR_BUILTIN_VALUE_CALLING_CONVENTION 2
+#define ZIR_BUILTIN_VALUE_ADDRESS_SPACE 3
+#define ZIR_BUILTIN_VALUE_FLOAT_MODE 4
+#define ZIR_BUILTIN_VALUE_REDUCE_OP 5
+#define ZIR_BUILTIN_VALUE_CALL_MODIFIER 6
+#define ZIR_BUILTIN_VALUE_PREFETCH_OPTIONS 7
+#define ZIR_BUILTIN_VALUE_EXPORT_OPTIONS 8
+#define ZIR_BUILTIN_VALUE_EXTERN_OPTIONS 9
+#define ZIR_BUILTIN_VALUE_TYPE_INFO 10
+#define ZIR_BUILTIN_VALUE_BRANCH_HINT 11
+#define ZIR_BUILTIN_VALUE_CLOBBERS 12
+#define ZIR_BUILTIN_VALUE_CALLING_CONVENTION_C 13
+#define ZIR_BUILTIN_VALUE_CALLING_CONVENTION_INLINE 14
+
 // Ast.Node.OptionalOffset.none = maxInt(i32).
 #define AST_NODE_OFFSET_NONE ((int32_t)0x7FFFFFFF)