Everywhere: Add "free" warnings

The following warnings do not occur anywhere in the codebase and so
enabling them is effectivly free:
 * `-Wcast-align`
 * `-Wduplicated-cond`
 * `-Wformat=2`
 * `-Wlogical-op`
 * `-Wmisleading-indentation`
 * `-Wunused`

These are taken as a strict subset of the list in SerenityOS#5487.

CMakeLists.txt

@@ -161,15 +161,22 @@ endif()
 add_compile_options(-Wall)
 add_compile_options(-Wextra)
 
+# The following warnings are sorted by the "base" name (the part excluding the initial Wno or W).
 add_compile_options(-Wno-address-of-packed-member)
+add_compile_options(-Wcast-align)
 add_compile_options(-Wcast-qual)
 add_compile_options(-Wno-deprecated-copy)
+add_compile_options(-Wduplicated-cond)
 add_compile_options(-Wno-expansion-to-defined)
+add_compile_options(-Wformat=2)
 add_compile_options(-Wimplicit-fallthrough)
+add_compile_options(-Wlogical-op)
+add_compile_options(-Wmisleading-indentation)
 add_compile_options(-Wmissing-declarations)
 add_compile_options(-Wno-nonnull-compare)
 add_compile_options(-Wno-unknown-warning-option)
 add_compile_options(-Wundef)
+add_compile_options(-Wunused)
 add_compile_options(-Wwrite-strings)
 
 add_compile_options(-ffile-prefix-map=${CMAKE_SOURCE_DIR}=.)