On macOS CI this was failing with:
```
FAIL: test_dsym (TestCPPEnumPromotion.TestCPPEnumPromotion)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 1784, in test_method
return attrvalue(self)
File "/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/test/API/lang/cpp/enum_promotion/TestCPPEnumPromotion.py", line 28, in test
self.expect_expr("+EnumUChar::UChar", result_type=UChar_promoted.type.name)
File "/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 2540, in expect_expr
value_check.check_value(self, eval_result, str(eval_result))
File "/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 299, in check_value
test_base.assertSuccess(val.GetError())
File "/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 2575, in assertSuccess
self.fail(self._formatMessage(msg, "'{}' is not success".format(error)))
AssertionError: 'error: <user expression 0>:1:2: use of undeclared identifier 'EnumUChar'
1 | +EnumUChar::UChar
| ^
' is not success
```
But only for the `dSYM` variant of the test.
Looking at the dSYM, none of the enums are actually preserved in the debug-info. We have to actually use the enum types in source to get dsymutil to preserve them. This patch does just that.
The information about an enum's best promotion type is discarded after
compilation and is not present in debug info. This patch repeats the
same analysis of each enum value as in the front-end to determine the
best promotion type during DWARF info parsing.
Fixes#86989
