General: Catch more expressions with no effect on MSVC

MSVC lets us fine-tune catching expressions with no side-effects a
little more.

src/CMakeLists.txt

@@ -45,6 +45,10 @@ if (MSVC)
 
         # Warnings
         /W3
+        /we4547 # 'operator' : operator before comma has no effect; expected operator with side-effect
+        /we4548 # Expression before comma has no effect; expected expression with side-effect
+        /we4549 # 'operator1': operator before comma has no effect; did you intend 'operator2'?
+        /we4555 # Expression has no effect; expected expression with side-effect
         /we4834 # Discarding return value of function with 'nodiscard' attribute
     )