[FIR] Add kind for back edges in CFG

compiler/fir/analysis-tests/testData/resolve/smartcasts/boundSmartcasts/boundSmartcastsInBranches.dot

@@ -124,8 +124,8 @@ digraph boundSmartcastsInBranches_kt {
     36 -> {37};
     37 -> {38};
     38 -> {39};
-    39 -> {17};
     39 -> {40} [style=dotted];
+    39 -> {17} [color=green style=dashed];
     40 -> {41} [style=dotted];
     41 -> {42} [style=dotted];
     42 -> {29} [style=dotted];
@@ -133,7 +133,7 @@ digraph boundSmartcastsInBranches_kt {
     44 -> {45};
     45 -> {46};
     46 -> {47};
-    47 -> {19};
+    47 -> {19} [color=green style=dashed];
 
     subgraph cluster_12 {
         color=red

compiler/fir/analysis-tests/testData/resolve/smartcasts/loops/dataFlowInfoFromWhileCondition.dot

@@ -91,6 +91,6 @@ digraph dataFlowInfoFromWhileCondition_kt {
     26 -> {27};
     27 -> {28};
     28 -> {29};
-    29 -> {14};
+    29 -> {14} [color=green style=dashed];
 
 }

compiler/fir/analysis-tests/testData/resolve/smartcasts/loops/endlessLoops.dot

@@ -93,7 +93,7 @@ digraph endlessLoops_kt {
     25 -> {16} [style=dotted];
     26 -> {16};
     27 -> {28};
-    28 -> {8};
+    28 -> {8} [color=green style=dashed];
     29 -> {30};
     30 -> {5};
 
@@ -173,7 +173,7 @@ digraph endlessLoops_kt {
     52 -> {41} [style=dotted];
     53 -> {41};
     54 -> {55};
-    55 -> {35};
+    55 -> {35} [color=green style=dashed];
     56 -> {57};
     57 -> {32};
 
@@ -287,7 +287,7 @@ digraph endlessLoops_kt {
     91 -> {82} [style=dotted];
     92 -> {82};
     93 -> {94};
-    94 -> {62};
+    94 -> {62} [color=green style=dashed];
     95 -> {96};
     96 -> {59};
 
@@ -372,7 +372,7 @@ digraph endlessLoops_kt {
     120 -> {121} [style=dotted];
     121 -> {122} [style=dotted];
     122 -> {123} [style=dotted];
-    123 -> {101} [style=dotted];
+    123 -> {101} [color=green style=dotted];
     124 -> {125};
     125 -> {98};
 
@@ -451,8 +451,8 @@ digraph endlessLoops_kt {
     147 -> {148};
     148 -> {149};
     149 -> {150};
-    150 -> {130};
     150 -> {129} [style=dotted];
+    150 -> {130} [color=green style=dashed];
     151 -> {152};
     152 -> {127};
 
@@ -531,8 +531,8 @@ digraph endlessLoops_kt {
     174 -> {175};
     175 -> {176};
     176 -> {177};
-    177 -> {157};
     177 -> {156} [style=dotted];
+    177 -> {157} [color=green style=dashed];
     178 -> {179};
     179 -> {154};
 
@@ -577,8 +577,8 @@ digraph endlessLoops_kt {
     189 -> {190};
     190 -> {191};
     191 -> {192};
-    192 -> {184};
     192 -> {183} [style=dotted];
+    192 -> {184} [color=green style=dashed];
     193 -> {194} [style=dotted];
     194 -> {181} [style=dotted];
 

compiler/fir/analysis-tests/testData/resolve/smartcasts/smartcastToNothing.dot

@@ -250,7 +250,7 @@ digraph smartcastToNothing_kt {
     81 -> {70} [style=dotted];
     82 -> {70} [style=dotted];
     83 -> {84} [style=dotted];
-    84 -> {56} [style=dotted];
+    84 -> {56} [color=green style=dotted];
     85 -> {86 87};
     86 -> {88};
     87 -> {48} [style=dotted];