[scudo] Clean up Zircon header file uses

Make fuchsia.h and fuchsia.cpp each include what they use.

GitOrigin-RevId: a27b9139ab1bbdc93afaf240de2c2b9e45092884
diff --git a/fuchsia.cpp b/fuchsia.cpp
index 3b473bc..088f077 100644
--- a/fuchsia.cpp
+++ b/fuchsia.cpp
@@ -17,6 +17,7 @@
 #include <lib/sync/mutex.h> // for sync_mutex_t
 #include <stdlib.h>         // for getenv()
 #include <zircon/compiler.h>
+#include <zircon/process.h>
 #include <zircon/sanitizer.h>
 #include <zircon/syscalls.h>
 
diff --git a/fuchsia.h b/fuchsia.h
index d6993f8..c1dfd76 100644
--- a/fuchsia.h
+++ b/fuchsia.h
@@ -13,7 +13,8 @@
 
 #if SCUDO_FUCHSIA
 
-#include <zircon/process.h>
+#include <stdint.h>
+#include <zircon/types.h>
 
 namespace scudo {