[NDK][NTOS] Add global definition of INIT_FUNCTION/INIT_SECTION (#779)

* Add an NDK header to define INIT_FUNCTION/INIT_SECTION globally
* Use _declspec(allocate(x)) and _declspec(code_seg(x)) on MSVC versions that support it
* Use INIT_FUNCTION on functions only and INIT_SECTION on data only (required by MSVC)
* Place INIT_FUNCTION before the return type (required by MSVC)
* Make sure declarations and implementations share the same modifiers (required by MSVC)
* Add a global linker option to suppress warnings about defined but unused INIT section
* Merge INIT section into .text in freeldr

win32ss/gdi/eng/ldevobj.h

@@ -51,6 +51,7 @@ NTAPI
 EngGetLDEV(
     PDEVMODEW pdm);
 
+INIT_FUNCTION
 NTSTATUS
 APIENTRY
 DriverEntry (

win32ss/user/ntuser/main.c

@@ -904,7 +904,7 @@ DriverUnload(IN PDRIVER_OBJECT DriverObject)
 /*
  * This definition doesn't work
  */
-INIT_SECTION
+INIT_FUNCTION
 NTSTATUS
 APIENTRY
 DriverEntry(

win32ss/win32kp.h

@@ -10,14 +10,6 @@
 
 #pragma once
 
-#ifdef __GNUC__
-#define INIT_SECTION __attribute__((section ("INIT")))
-#define INIT_FUNCTION INIT_SECTION
-#else
-#define INIT_SECTION  /* Done via alloc_text for MSC */
-#define INIT_FUNCTION INIT_SECTION
-#endif
-
 /* Enable debugging features */
 #define GDI_DEBUG 0
 #define DBG_ENABLE_GDIOBJ_BACKTRACES 0