[Ada] System.OS_Interface: fix Critical_Section.SpinCount type

2019-07-09  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* libgnarl/s-osinte__mingw.ads (CRITICAL_SECTION): Use proper
	type for SpinCount component.

From-SVN: r273291

gcc/ada/ChangeLog

+2019-07-09  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* libgnarl/s-osinte__mingw.ads (CRITICAL_SECTION): Use proper
+	type for SpinCount component.
+
 2019-07-09  Justin Squirek  <squirek@adacore.com>
 
 	* exp_ch4.adb (Expand_N_Allocator): Add conditional to detect

gcc/ada/libgnarl/s-osinte__mingw.ads

@@ -369,7 +369,7 @@ private
       --  section for the resource.
 
       LockSemaphore : Win32.HANDLE;
-      SpinCount     : Win32.DWORD;
+      SpinCount     : Interfaces.C.size_t;
    end record;
 
 end System.OS_Interface;