[FIR-TEST] Move analysis tests to separate module

compiler/fir/analysis-tests/testData/resolve/arguments/fieldPlusAssign.kt

@@ -0,0 +1,10 @@
+var x: Int = 1
+    set(value) {
+        field += value
+    }
+
+val y: Int = 1
+    get() {
+        <!VARIABLE_EXPECTED!>field<!> += 1
+        return 1
+    }