Revert "[libc] Add rep;movsb as an accelerator under x86"

This reverts commit 1c7160300db124468ef4a26ec55ad3d6e6527a69.

GitOrigin-RevId: d01ae990e1fd6561ed86dc8004a7147dd09fb13c
diff --git a/src/string/memory_utils/elements_x86.h b/src/string/memory_utils/elements_x86.h
index 9521e06..2873fff 100644
--- a/src/string/memory_utils/elements_x86.h
+++ b/src/string/memory_utils/elements_x86.h
@@ -160,12 +160,6 @@
 using _128 = __llvm_libc::Repeated<_8, 16>;
 #endif
 
-struct Accelerator {
-  static void Copy(char *dst, const char *src, size_t count) {
-    asm volatile("rep movsb" : "+D"(dst), "+S"(src), "+c"(count) : : "memory");
-  }
-};
-
 } // namespace x86
 } // namespace __llvm_libc