improve type stability of handle_message(logger, ...

Author: ranocha

base/logging.jl

@@ -671,7 +671,7 @@ function handle_message(logger::SimpleLogger, level::LogLevel, message, _module,
         remaining > 0 || return
     end
     buf = IOBuffer()
-    stream = logger.stream
+    stream::IO = logger.stream
     if !(isopen(stream)::Bool)
         stream = stderr
     end

stdlib/Logging/src/ConsoleLogger.jl

@@ -117,7 +117,7 @@ function handle_message(logger::ConsoleLogger, level::LogLevel, message, _module
     # Generate a text representation of the message and all key value pairs,
     # split into lines.
     msglines = [(indent=0, msg=l) for l in split(chomp(convert(String, string(message))::String), '\n')]
-    stream = logger.stream
+    stream::IO = logger.stream
     if !(isopen(stream)::Bool)
         stream = stderr
     end