This adds automatic scope management and indentation to the logs to make
them more structured. Also adds some additional logging.
Here's an example of what it can look like now:
```
[swiftify:593] Checking 'CountedByProtocol' protocol for methods with bounds and lifetime info
[swiftify:350] | Checking 'simple::' for bounds and lifetime info
[swiftify:411] | | Checking parameter 'len' with type 'int'
[swiftify:411] | | Checking parameter 'p' with type 'int * __counted_by(len)'
[swiftify:435] | | | Found bounds info 'int * __counted_by(len)'
[swiftify:350] | Checking 'shared:::' for bounds and lifetime info
[swiftify:411] | | Checking parameter 'len' with type 'int'
[swiftify:411] | | Checking parameter 'p1' with type 'int * __counted_by(len)'
[swiftify:435] | | | Found bounds info 'int * __counted_by(len)'
[swiftify:411] | | Checking parameter 'p2' with type 'int * __counted_by(len)'
[swiftify:435] | | | Found bounds info 'int * __counted_by(len)'
[swiftify:350] | Checking 'complexExpr:::' for bounds and lifetime info
[swiftify:411] | | Checking parameter 'len' with type 'int'
[swiftify:411] | | Checking parameter 'offset' with type 'int'
[swiftify:411] | | Checking parameter 'p' with type 'int * __counted_by(len - offset)'
[swiftify:435] | | | Found bounds info 'int * __counted_by(len - offset)'
[swiftify:350] | Checking 'nullUnspecified::' for bounds and lifetime info
[swiftify:411] | | Checking parameter 'len' with type 'int'
[swiftify:411] | | Checking parameter 'p' with type 'int * __counted_by(len) _Null_unspecified'
[swiftify:435] | | | Found bounds info 'int * __counted_by(len) _Null_unspecified'
[swiftify:350] | Checking 'nonnull::' for bounds and lifetime info
[swiftify:411] | | Checking parameter 'len' with type 'int'
[swiftify:411] | | Checking parameter 'p' with type 'int * __counted_by(len) _Nonnull'
[swiftify:435] | | | Found bounds info 'int * __counted_by(len) _Nonnull'
[swiftify:350] | Checking 'nullable::' for bounds and lifetime info
[swiftify:411] | | Checking parameter 'len' with type 'int'
[swiftify:411] | | Checking parameter 'p' with type 'int * __counted_by(len) _Nullable'
[swiftify:435] | | | Found bounds info 'int * __counted_by(len) _Nullable'
[swiftify:350] | Checking 'returnPointer:' for bounds and lifetime info
[swiftify:379] | | Found bounds info 'int * __counted_by(len)' on return value
[swiftify:411] | | Checking parameter 'len' with type 'int'
[swiftify:350] | Checking 'staticMethod::' for bounds and lifetime info
[swiftify:411] | | Checking parameter 'len' with type 'int'
[swiftify:411] | | Checking parameter 'p' with type 'int * __counted_by(len)'
[swiftify:435] | | | Found bounds info 'int * __counted_by(len)'
```
This updates SwiftifyImportProtocolPrinter such that it no longer emits
anything for methods without bounds or lifetime info. Previously we
would not attach the macro if no methods in the protocol contained
bounds or lifetime info. However if one of the methods did, we would
still emit `.method(signature: "func foo()", paramInfo: [])` for the
methods without bounds of lifetime info. This would result in overloads
being generated, like so:
```
@_alwaysEmitIntoClient @_disfavoredOverload public
func foo() {
return unsafe foo()
}
```
As part of this change, SwiftifyImportPrinter is now an abstract parent
type for SwiftifyImportProtocolPrinter, and the new
SwiftifyImportFunctionPrinter. Instead of SwiftifyImportProtocolPrinter
inheriting the function printing, `printMethod` instead creates a new
SwiftifyImportFunctionPrinter each time, with a new output string. If it
output anything interesting the result is forwarded, otherwise it is
discarded.
...with bounds attributes
This creates safe overloads for any methods in the protocol annotated
with bounds information. Updates _SwiftifyImportProtocol to make the
added overloads in the protocol public.
rdar://144335990
This code doesn't interact that much with the rest of ClangImporter, and
will continue to grow. Keeping it in a separate file makes it easier to
navigate.
