Clean up some code

- Use good ELF technique in cosmo_dlopen()
- Make strerror() conform more to other libc impls
- Introduce __clear_cache() and use it in cosmo_dlopen()
- Remove libc/fmt/fmt.h header (trying to kill off LIBC_FMT)

third_party/xxhash/cli/xsum_os_specific.c

@@ -91,7 +91,6 @@
 #include "libc/nt/winsock.h" /* DeviceIoControl, HANDLE, FSCTL_SET_SPARSE */
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/cli/xsum_os_specific.h

@@ -30,7 +30,6 @@
 #include "third_party/xxhash/cli/xsum_config.h"
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/tests/bench/benchfn.c

@@ -56,7 +56,6 @@
 #if defined(DEBUG) && (DEBUG >= 1)
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/tests/bench/bhDisplay.c

@@ -45,7 +45,6 @@
 #include "third_party/musl/rand48.h"   /* rand */
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/tests/bench/main.c

@@ -29,7 +29,6 @@
 
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/tests/bench/timefn.c

@@ -38,7 +38,6 @@
 #include "third_party/musl/rand48.h"   /* abort */
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"
@@ -125,7 +124,6 @@ PTime UTIL_getSpanTimeNano(UTIL_time_t clockStart, UTIL_time_t clockEnd)
 #include "third_party/musl/rand48.h"   /* abort */
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/tests/collisions/main.c

@@ -65,7 +65,6 @@
 #include "libc/str/str.h"   /* memset */
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/tests/collisions/threading.h

@@ -63,7 +63,6 @@ extern "C" {
 #include "libc/nt/winsock.h"
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/tests/generate_unicode_test.c

@@ -42,7 +42,6 @@
 #define _CRT_SECURE_NO_WARNINGS /* Silence warnings on MSVC */
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/tests/multiInclude.c

@@ -28,7 +28,6 @@
 
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/xxh_x86dispatch.c

@@ -200,7 +200,6 @@ extern "C" {
 /* debug logging */
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"

third_party/xxhash/xxhash.h

@@ -144,7 +144,6 @@
  * @code{.c}
  *   #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"
@@ -1360,7 +1359,6 @@ XXH_PUBLIC_API XXH_PUREF XXH128_hash_t XXH128(XXH_NOESCAPE const void* data, siz
  * @code{.c}
  *    #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
-#include "libc/fmt/fmt.h"
 #include "libc/stdio/dprintf.h"
 #include "libc/stdio/stdio.h"
 #include "libc/temp.h"