PS: Add tests with arrays.

Author: MathiasVP

powershell/ql/test/library-tests/dataflow/fields/test.ps1

@@ -4,3 +4,28 @@ Sink $a.f # $ hasValueFlow=1
 $a.f = Source "2"
 $a.f = 0
 Sink $a.f # clean
+
+$arr1[3] = Source "3"
+Sink $arr1[3] # $ MISSING: hasValueFlow=3
+Sink $arr1[4] # clean
+
+$arr2[$unknown] = Source "4"
+Sink $arr2[4] # $ MISSING: hasValueFlow=4
+
+$arr3[3] = Source "5"
+Sink $arr3[$unknown] # $ MISSING: hasValueFlow=5
+
+$arr4[$unknown1] = Source "6"
+Sink $arr4[$unknown2] # $ MISSING: hasValueFlow=6
+
+$arr5[$unknown3][1] = Source "7"
+Sink $arr5[$unknown3][1] # $ MISSING: hasValueFlow=7
+Sink $arr5[$unknown3][2] # clean
+
+$arr6[1][$unknown4] = Source "8"
+Sink $arr6[1][$unknown4] # $ MISSING: hasValueFlow=8
+Sink $arr6[2][$unknown4] # clean
+
+$arr7[$unknown5][$unknown6] = Source "9"
+Sink $arr7[1][2] # $ MISSING: hasValueFlow=9
+Sink $arr7[$unknown7][$unknown8] # $ MISSING: hasValueFlow=9