vulkan: Support VK_EXT_debug_report in loader and nulldrv

* Add extension to vulkan.api.
* Fix a few errors in upstream vk_ext_debug_report.h; bugs filed.
* Loader enumerates extension iff the driver supports it.
  - TODO: Also enumerate if any layers that support it are implicitly
    enabled.
  - Note extension may still be enabled if any layer supports it.
* Add loader bottom procs for the extension functions. These will call
  through to the driver version if the driver supports the extension.
* Add no-op support to nulldrv, mostly for testing the loader.

Change-Id: I092d2da56ee4c64498f8edae75e0d995478bb6f2
(cherry picked from commit a5ef7c27bc85e3628814532a32ffb9a5c33c4b73)
diff --git a/vulkan/nulldrv/Android.mk b/vulkan/nulldrv/Android.mk
index 2db6138..77d4746 100644
--- a/vulkan/nulldrv/Android.mk
+++ b/vulkan/nulldrv/Android.mk
@@ -16,12 +16,13 @@
 include $(CLEAR_VARS)
 
 LOCAL_CLANG := true
-LOCAL_CFLAGS := -std=c99 -fvisibility=hidden -fstrict-aliasing
-LOCAL_CFLAGS += -DLOG_TAG=\"vknulldrv\"
-LOCAL_CFLAGS += -Weverything -Werror \
+LOCAL_CFLAGS := -std=c99 -fvisibility=hidden -fstrict-aliasing \
+	-DLOG_TAG=\"vknulldrv\" \
+	-Weverything -Werror \
 	-Wno-padded \
 	-Wno-undef \
 	-Wno-zero-length-array
+#LOCAL_CFLAGS += -DLOG_NDEBUG=0
 LOCAL_CPPFLAGS := -std=c++1y \
 	-Wno-c++98-compat-pedantic \
 	-Wno-c99-extensions