fix: more MSVC warnings (#5137)

src/CMakeLists.txt

@@ -935,6 +935,7 @@ target_compile_definitions(${LIBRARY_PROJECT} PUBLIC
     AB_CUSTOM_SETTINGS
     IRC_STATIC
     IRC_NAMESPACE=Communi
+    $<$<BOOL:${WIN32}>:_WIN32_WINNT=0x0A00> # Windows 10
     )
 
 if (USE_SYSTEM_QTKEYCHAIN)
@@ -1048,10 +1049,6 @@ if (MSVC)
     # Someone adds /W3 before we add /W4.
     # This makes sure, only /W4 is specified.
     string(REPLACE "/W3" "/W4" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-    # 4505 - "unreferenced local version has been removed"
-    #        Although this might give hints on dead code,
-    #        there are some cases where it's distracting.
-    #
     # 4100 - "unreferenced formal parameter"
     #        There are a lot of functions and methods where
     #        an argument was given a name but never used.
@@ -1062,6 +1059,11 @@ if (MSVC)
     #        These are implicit conversions from size_t to int/qsizetype.
     #        We don't use size_t in a lot of cases, since
     #        Qt doesn't use it - it uses int (or qsizetype in Qt6).
+    #
+    # 4458 - "declaration of 'identifier' hides class member"
+    #        We have a rule of exclusively using `this->`
+    #        to access class members, thus it's fine to reclare a variable
+    #        with the same name as a class member.
     target_compile_options(${LIBRARY_PROJECT} PUBLIC
         /W4
         # 5038 - warnings about initialization order
@@ -1069,9 +1071,9 @@ if (MSVC)
         # 4855 - implicit capture of 'this' via '[=]' is deprecated
         /w14855
         # Disable the following warnings (see reasoning above)
-        /wd4505
         /wd4100
         /wd4267
+        /wd4458
         # Enable updated '__cplusplus' macro - workaround for CMake#18837
         /Zc:__cplusplus
     )