feat: kernel and libc performance improvements

programs/lib/libc/libc.c

@@ -417,9 +417,9 @@ void *memchr(const void *s, int c, size_t n) {
 }
 
 size_t strlen(const char *s) {
-    size_t len = 0;
-    while (s[len]) len++;
-    return len;
+    const char *p = s;
+    while (*p) p++;
+    return p - s;
 }
 
 size_t strspn(const char *s, const char *accept) {
@@ -441,8 +441,9 @@ size_t strcspn(const char *s, const char *reject) {
 }
 
 int strcmp(const char *a, const char *b) {
-    while (*a && *a == *b) { a++; b++; }
-    return (unsigned char)*a - (unsigned char)*b;
+    const char *pa = a, *pb = b;
+    while (*pa && *pa == *pb) { pa++; pb++; }
+    return (unsigned char)*pa - (unsigned char)*pb;
 }
 
 int strncmp(const char *a, const char *b, size_t n) {