Added comments to DangerousGetReference tests

Author: Sergio0694

UnitTests/UnitTests.HighPerformance.Shared/Extensions/Test_ArrayExtensions.1D.cs

@@ -17,6 +17,12 @@ public void Test_ArrayExtensions_DangerousGetReference()
         {
             string[] tokens = "aa,bb,cc,dd,ee,ff,gg,hh,ii".Split(',');
 
+            // In all these "DangerousGetReference" tests, we need to ensure that a reference to a given
+            // item within an array is effectively the one corresponding to the one whe expect, which is
+            // either a reference to the first item if we use "DangerousGetReference", or one to the n-th
+            // item if we use "DangerousGetReferenceAt". So all these tests just invoke the API and then
+            // compare the returned reference against an existing baseline (like the built-in array indexer)
+            // to ensure that the two are the same. These are all managed references, so no need for pinning.
             ref string r0 = ref Unsafe.AsRef(tokens.DangerousGetReference());
             ref string r1 = ref Unsafe.AsRef(tokens[0]);
 

UnitTests/UnitTests.HighPerformance.Shared/Extensions/Test_ArrayExtensions.2D.cs

@@ -24,6 +24,7 @@ public void Test_ArrayExtensions_2D_DangerousGetReference_Int()
                 { 9, 10, 11, 12 }
             };
 
+            // See comments in Test_ArrayExtensions.1D for how these tests work
             ref int r0 = ref array.DangerousGetReference();
             ref int r1 = ref array[0, 0];
 

UnitTests/UnitTests.HighPerformance.Shared/Extensions/Test_ArrayExtensions.3D.cs

@@ -16,6 +16,7 @@ public void Test_ArrayExtensions_3D_DangerousGetReference_Int()
         {
             int[,,] array = new int[10, 20, 12];
 
+            // See comments in Test_ArrayExtensions.1D for how these tests work
             ref int r0 = ref array.DangerousGetReference();
             ref int r1 = ref array[0, 0, 0];