Add SKIP_JAVAC in tests where behaviour has diverged with IDEA resolve

See a71f09022c

compiler/testData/javac/diagnostics/tests/imports/ClassImportsConflicting.kt

@@ -1,3 +1,4 @@
+// SKIP_JAVAC
 // FILE: b.kt
 package b
 

compiler/testData/javac/diagnostics/tests/imports/NestedAndTopLevelClassClash.kt

@@ -1,3 +1,4 @@
+// SKIP_JAVAC
 // FILE: a/B.java
 package a;
 

compiler/testData/javac/diagnostics/tests/imports/NestedClassClash.kt

@@ -1,3 +1,4 @@
+// SKIP_JAVAC
 // FILE: a/A.java
 package a;