vulkan: Update vulkan headers to 1.0.38

Catches up with the current upstream header. Preserves the local changes
for incremental present.

V2: Fix indentation issues
V3: Add missing struct and defines for EXT_validation_flags

Change-Id: I6e4f44e0eba8de00b010a6918ec2ba92614cc6bc
Test: Ensured cube demo still works
diff --git a/vulkan/api/platform.api b/vulkan/api/platform.api
index 7aa19e7..fb8e3ce 100644
--- a/vulkan/api/platform.api
+++ b/vulkan/api/platform.api
@@ -48,3 +48,5 @@
 // VK_USE_PLATFORM_WIN32_KHR
 @internal type void* HINSTANCE
 @internal type void* HWND
+@internal type void* HANDLE
+@internal class SECURITY_ATTRIBUTES {}