StringView+apps: Add a _sv literal suffix to not confuse function overloads

C++ was being naughty and implicitly casting our fallback const char* to a boolean.

apps/date.cpp

@@ -10,7 +10,7 @@ int main(int argc, char** argv)
     StringView date;
 
     ArgumentParser parser;
-    parser.add_value_argument(date, 'd', "date", false);
+    parser.add_value_argument(date, 'd', "date"_sv, false);
     parser.parse(argc, argv);
 
     time_t now;

apps/edit.cpp

@@ -10,7 +10,7 @@ int main(int argc, char** argv)
     StringView pathname;
 
     ArgumentParser parser;
-    parser.add_positional_argument(pathname, "file", true);
+    parser.add_positional_argument(pathname, "file"_sv, true);
     parser.parse(argc, argv);
 
     f = fopen(pathname.chars(), "w");

apps/ls.cpp

@@ -12,9 +12,9 @@ int main(int argc, char** argv)
     bool show_almost_all;
 
     ArgumentParser parser;
-    parser.add_positional_argument(pathname, "directory", "/");
+    parser.add_positional_argument(pathname, "directory"_sv, "/"_sv);
-    parser.add_switch_argument(show_all, 'a', "all");
+    parser.add_switch_argument(show_all, 'a', "all"_sv);
-    parser.add_switch_argument(show_almost_all, 'A', "almost-all");
+    parser.add_switch_argument(show_almost_all, 'A', "almost-all"_sv);
     parser.parse(argc, argv);
 
     DIR* dp = opendir(pathname.chars());

libluna/include/luna/StringView.h

@@ -52,3 +52,13 @@ class StringView
 
     usize m_length { 0 };
 };
+
+inline StringView operator""_sv(const char* cstring)
+{
+    return StringView { cstring };
+}
+
+inline StringView operator""_sv(const char* cstring, usize length)
+{
+    return StringView { cstring, length };
+}