use proxy headers for size_t/ssize_t

Author: uzairnawaz

libc/src/__support/OSUtil/mmap.h

@@ -9,9 +9,10 @@
 #ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_MMAP_H
 #define LLVM_LIBC_SRC___SUPPORT_OSUTIL_MMAP_H
 
+#include "hdr/types/off_t.h"
+#include "hdr/types/size_t.h"
 #include "src/__support/error_or.h"
 #include "src/__support/macros/config.h"
-#include <sys/mman.h> // For size_t and off_t
 
 namespace LIBC_NAMESPACE_DECL {
 namespace internal {

libc/src/__support/OSUtil/munmap.h

@@ -9,9 +9,10 @@
 #ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_MUNMAP_H
 #define LLVM_LIBC_SRC___SUPPORT_OSUTIL_MUNMAP_H
 
+#include "hdr/types/off_t.h"
+#include "hdr/types/size_t.h"
 #include "src/__support/error_or.h"
 #include "src/__support/macros/config.h"
-#include <sys/mman.h> // For size_t and off_t
 
 namespace LIBC_NAMESPACE_DECL {
 namespace internal {

libc/src/sys/mman/linux/mmap.cpp

@@ -19,11 +19,12 @@ LLVM_LIBC_FUNCTION(void *, mmap,
                     off_t offset)) {
   auto ptr = internal::mmap(addr, size, prot, flags, fd, offset);
 
-  if (ptr.has_value())
-    return ptr.value();
-
-  libc_errno = ptr.error();
-  return MAP_FAILED;
+  if (!ptr.has_value()) {
+    libc_errno = ptr.error();
+    return MAP_FAILED;
+  }
+  
+  return ptr.value();
 }
 
 } // namespace LIBC_NAMESPACE_DECL