misra: Fix crash on rule 9.x (#3024)

Closes ticket #10084

addons/misra_9.py

@@ -430,7 +430,7 @@ def createArrayChildrenDefs(ed, token, rawTokens = None):
             if foundToken and foundToken.next and foundToken.next.str == ']':
                 ed.markAsFlexibleArray(token)
 
-        if token.astOperand2 is not None:
+        if (token.astOperand2 is not None) and (token.astOperand2.getKnownIntValue() is not None):
             for i in range(token.astOperand2.getKnownIntValue()):
                 createChild(ed, token, i)
         else:

addons/test/misra/misra-test.c

@@ -444,6 +444,10 @@ void misra_9_struct_initializers() {
     dummy_struct dsd[]     = { [0] = 1 };                     // 9.5
 }
 
+void misra_9_broken_initializers() {
+    char a[UNKNOWN_MACRO] = { 19, 23, 0 };             // 18.8
+}
+
 void misra_9_2() {
     union misra_9_2_union {     // 19.2
         char c;