Fix crash in LuaPrint

src/basic/basic.h

@@ -221,7 +221,20 @@ For(arr.reverse_iter()) {
 #define For(array) ForItem(it, array)
 
 constexpr int64_t SLICE_LAST = INT64_MIN;
-int64_t           WideLength(wchar_t *string);
+inline int64_t    StringLen(char *string) {
+    if (!string) return 0;
+    int64_t i = 0;
+    while (string[i]) i += 1;
+    return i;
+}
+
+inline int64_t WideLength(wchar_t *string) {
+    if (!string) return 0;
+    int64_t len = 0;
+    while (*string++ != 0)
+        len++;
+    return len;
+}
 
 template <class T>
 struct Slice {
@@ -231,8 +244,8 @@ struct Slice {
     Slice() = default;
     Slice(T *s, int64_t l) : data(s), len(l) {}
 
-    Slice(char *s) : data(s), len(strlen(s)) {}
-    Slice(const char *s) : data((char *)s), len(strlen((char *)s)) {}
+    Slice(char *s) : data(s), len(StringLen(s)) {}
+    Slice(const char *s) : data((char *)s), len(StringLen((char *)s)) {}
     Slice(const char *s, int64_t l) : data((char *)s), len(l) {}
 
     Slice(wchar_t *s) : data(s), len(WideLength(s)) {}
@@ -1584,13 +1597,6 @@ String Format(Allocator allocator, const char *data, ...) PrintfFormatAttribute(
     return result;
 }
 
-int64_t WideLength(wchar_t *string) {
-    int64_t len = 0;
-    while (*string++ != 0)
-        len++;
-    return len;
-}
-
 String16 ToString16(Allocator allocator, String string) {
     Assert(sizeof(wchar_t) == 2);
     wchar_t *buffer = (wchar_t *)AllocSize(allocator, sizeof(wchar_t) * (string.len + 1));