Add some missing headers

When running clang-format which reorders headers, those are the ones
that came up as missing.

Signed-off-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>

source/lib/alignment.h

@@ -26,6 +26,8 @@
 #include "lib/sysdep/compiler.h"	// MSC_VERSION
 #include "lib/sysdep/arch.h"	// ARCH_AMD64
 
+#include <cstdint>
+
 template<typename T>
 inline bool IsAligned(T t, uintptr_t multiple)
 {

source/lib/code_annotation.h

@@ -30,6 +30,8 @@
 #include "lib/sysdep/compiler.h"
 #include "lib/sysdep/arch.h"	// ARCH_AMD64
 
+#include <cstddef>
+
 /**
  * mark a function parameter as unused and avoid
  * the corresponding compiler warning.

source/lib/status.h

@@ -161,6 +161,10 @@ To summarize: +/-1SHHCC (S=subsystem, HH=header, CC=code number)
 #ifndef INCLUDED_STATUS
 #define INCLUDED_STATUS
 
+#include "lib/types.h"
+
+#include <cstddef>
+
 // an integral type allows defining error codes in separate headers,
 // but is not as type-safe as an enum. use Lint's 'strong type' checking
 // to catch errors such as Status Func() { return 1; }.

source/lib/sysdep/os/unix/unix_executable_pathname.h

@@ -23,6 +23,8 @@
 #ifndef INCLUDED_UNIX_EXECUTABLE_PATHNAME
 #define INCLUDED_UNIX_EXECUTABLE_PATHNAME
 
+#include "lib/os_path.h"
+
 OsPath unix_ExecutablePathname();
 
 #endif  // INCLUDED_UNIX_EXECUTABLE_PATHNAME