Remove generated codegen tests, move all testData to box/

A single test file will be generated out of box/ directory

compiler/testData/codegen/box/instructions/swap/swapRefToSharedVarInt.kt

@@ -0,0 +1,11 @@
+fun box(): String {
+    var a: Int
+    a = 12
+    fun f() {
+        foo(a)
+    }
+
+    return "OK"
+}
+
+fun foo(l: Int) {}

compiler/testData/codegen/box/instructions/swap/swapRefToSharedVarLong.kt

@@ -0,0 +1,13 @@
+//KT-3042 Attempt to split long or double on the stack excepion
+
+fun box(): String {
+    var a: Long
+    a = 12.toLong()
+    fun f() {
+        foo(a)
+    }
+
+    return "OK"
+}
+
+fun foo(l: Long) {}