FIR DFA: make continue jump to condition entry, not loop entry

It's also not a backwards jump in do-while, unless it's in the loop's
condition, which is a stupid "feature" IMO. As you can probably tell
from the comments added in this commit.

compiler/fir/analysis-tests/testData/resolve/cfg/jumps.dot

@@ -354,7 +354,7 @@ digraph jumps_kt {
     113 -> {114};
     114 -> {115};
     115 -> {116} [style=dotted];
-    115 -> {102} [color=green style=dashed];
+    115 -> {103} [color=green style=dashed];
     116 -> {117} [style=dotted];
     117 -> {118} [style=dotted];
     118 -> {119} [style=dotted];

compiler/fir/analysis-tests/testData/resolve/cfg/tryCatch.dot

@@ -324,7 +324,7 @@ digraph tryCatch_kt {
     96 -> {97};
     97 -> {98};
     98 -> {99} [style=dotted];
-    98 -> {46} [color=green style=dashed];
+    98 -> {47} [color=green style=dashed];
     99 -> {100} [style=dotted];
     100 -> {101} [style=dotted];
     101 -> {102} [style=dotted];

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

@@ -136,7 +136,7 @@ digraph boundSmartcastsInBranches_kt {
     36 -> {37};
     37 -> {38};
     38 -> {39} [style=dotted];
-    38 -> {17} [color=green style=dashed];
+    38 -> {18} [color=green style=dashed];
     39 -> {40} [style=dotted];
     40 -> {41} [style=dotted];
     41 -> {42} [style=dotted];