Imported Upstream version 6.4.0.137

Former-commit-id: 943baa9f16a098c33e129777827f3a9d20da00d6

mcs/class/System.Private.CoreLib/System.Threading/StackCrawlMark.cs

@@ -0,0 +1,13 @@
+namespace System.Threading
+{
+	// declaring a local var of this enum type and passing it by ref into a function that needs to do a
+	// stack crawl will both prevent inlining of the calle and pass an ESP point to stack crawl to
+	// Declaring these in EH clauses is illegal; they must declared in the main method body
+	internal enum StackCrawlMark
+	{
+		LookForMe = 0,
+		LookForMyCaller = 1,
+		LookForMyCallersCaller = 2,
+		LookForThread = 3
+	}
+}