input_common/CMakeLists: Make some warnings errors

Makes the input_common code warnings consistent with the rest of the
codebase.

src/input_common/CMakeLists.txt

@@ -29,6 +29,35 @@ add_library(input_common STATIC
     udp/udp.h
 )
 
+if (MSVC)
+    target_compile_options(input_common PRIVATE
+        # 'expression' : signed/unsigned mismatch
+        /we4018
+        # 'argument' : conversion from 'type1' to 'type2', possible loss of data (floating-point)
+        /we4244
+        # 'conversion' : conversion from 'type1' to 'type2', signed/unsigned mismatch
+        /we4245
+        # 'operator': conversion from 'type1:field_bits' to 'type2:field_bits', possible loss of data
+        /we4254
+        # 'var' : conversion from 'size_t' to 'type', possible loss of data
+        /we4267
+        # 'context' : truncation from 'type1' to 'type2'
+        /we4305
+    )
+else()
+    target_compile_options(input_common PRIVATE
+        -Werror=conversion
+        -Werror=ignored-qualifiers
+        -Werror=implicit-fallthrough
+        -Werror=reorder
+        -Werror=shadow
+        -Werror=sign-compare
+        -Werror=unused-but-set-parameter
+        -Werror=unused-but-set-variable
+        -Werror=unused-variable
+    )
+endif()
+
 if(SDL2_FOUND)
     target_sources(input_common PRIVATE
         sdl/sdl_impl.cpp