Fix bugs and make code tinier

- Fixed bug where stdio eof wasn't being sticky
- Fixed bug where fseeko() wasn't clearing eof state
- Removed assert() usage from libc favoring _unassert() / _npassert()

libc/str/blake2.c

@@ -126,7 +126,7 @@ int BLAKE2B256_Update(struct Blake2b *b2b, const void *in_data, size_t len) {
     return 0;
   }
   // More input remains therefore we must have filled |b2b->block|.
-  assert(b2b->block_used == BLAKE2B_CBLOCK);
+  _unassert(b2b->block_used == BLAKE2B_CBLOCK);
   Blake2bTransform(b2b, b2b->block.words, BLAKE2B_CBLOCK,
                    /*is_final_block=*/0);
   b2b->block_used = 0;

libc/str/getcachesize.c

@@ -51,7 +51,7 @@ static unsigned _getcachesize_cpuid4(int type, int level) {
  * @return size in bytes, or 0 if unknown
  */
 unsigned _getcachesize(int type, int level) {
-  assert(1 <= type && type <= 3);
-  assert(level >= 1);
+  _unassert(1 <= type && type <= 3);
+  _unassert(level >= 1);
   return _getcachesize_cpuid4(type, level);
 }

libc/str/strchr.c

@@ -70,6 +70,6 @@ char *strchr(const char *s, int c) {
   } else {
     r = strchr_pure(s, c);
   }
-  assert(!r || *r || !(c & 255));
+  _unassert(!r || *r || !(c & 255));
   return (char *)r;
 }

libc/str/strchrnul.c

@@ -68,6 +68,6 @@ char *strchrnul(const char *s, int c) {
   } else {
     r = strchrnul_pure(s, c);
   }
-  assert((*r & 255) == (c & 255) || !*r);
+  _unassert((*r & 255) == (c & 255) || !*r);
   return (char *)r;
 }

libc/str/strnlen.c

@@ -17,9 +17,9 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
-#include "libc/intrin/bits.h"
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
+#include "libc/intrin/bits.h"
 #include "libc/str/str.h"
 
 static noasan size_t strnlen_x64(const char *s, size_t n, size_t i) {
@@ -52,7 +52,7 @@ noasan size_t strnlen(const char *s, size_t n) {
   for (;; ++i) {
     if (i == n || !s[i]) break;
   }
-  assert(i == n || (i < n && !s[i]));
+  _unassert(i == n || (i < n && !s[i]));
   if (IsAsan()) __asan_verify(s, i);
   return i;
 }

libc/str/strnlen16.c

@@ -32,6 +32,6 @@ noasan size_t strnlen16(const char16_t *s, size_t n) {
   for (i = 0;; ++i) {
     if (i == n || !s[i]) break;
   }
-  assert(i == n || (i < n && !s[i]));
+  _unassert(i == n || (i < n && !s[i]));
   return i;
 }

libc/str/strnlen_s.c

@@ -56,6 +56,6 @@ noasan size_t strnlen_s(const char *s, size_t n) {
   for (;; ++i) {
     if (i == n || !s[i]) break;
   }
-  assert(i == n || (i < n && !s[i]));
+  _unassert(i == n || (i < n && !s[i]));
   return i;
 }

libc/str/strxfrm.c

@@ -42,6 +42,6 @@
  * @note if dest is NULL, count has to be zero
  */
 size_t strxfrm(char *dest, const char *src, size_t count) {
-  assert(dest == NULL ? count == 0 : 1);
+  _unassert(dest == NULL ? count == 0 : 1);
   return strlcpy(dest, src, count);
 }