Minor: don't trim file content in KotlinTestUtils#doLoadFile

compiler/testData/resolvedCalls/invoke/bothReceivers.txt

@@ -7,6 +7,7 @@ fun bar(f: Foo) {
 }
 
 
+
 Resolved call:
 
 Resulting descriptor: fun Int.invoke(): Unit defined in Foo

compiler/testData/resolvedCalls/invoke/dispatchReceiverAsReceiverForInvoke.txt

@@ -7,6 +7,7 @@ fun bar(f: Foo) {
 }
 
 
+
 Resolved call:
 
 Resulting descriptor: fun invoke(): Unit defined in Foo

compiler/testData/resolvedCalls/invoke/extensionReceiverAsReceiverForInvoke.txt

@@ -6,6 +6,7 @@ fun bar(f: Foo) {
 }
 
 
+
 Resolved call:
 
 Resulting descriptor: fun Foo.invoke(): Unit defined in root package

compiler/testData/resolvedCalls/invoke/implicitReceiverForInvoke.txt

@@ -5,6 +5,7 @@ fun bar(f: Int.() -> Unit, i: Int) {
 }
 
 
+
 Resolved call:
 
 Resulting descriptor: operator fun Int.invoke(): Unit defined in kotlin.Function1