Clean up fall-back logic in IncrementalCompilerRunner

Make it clear that there 3 distinct cases:
   1. Incremental compilation completed with an ExitCode.
   2. Incremental compilation was not possible for some valid reason
      (e.g., for a clean build), and we will perform non-incremental
      compilation.
   3. Incremental compilation failed with an exception.
      In this case, we will:
        - Print a warning with a stack trace
        - Ask the user to file a bug
        - Collect rebuild reason enum for analytics
           + TODO: Collect the stack trace too
        - Fall back to non-incremental compilation

Test: Existing BaseIncrementalCompilationMultiProjectIT.testFailureHandling_UserError,
      Updated BaseIncrementalCompilationMultiProjectIT.testFailureHandling_ToolError

^KT-53015: In progress

build-common/src/org/jetbrains/kotlin/build/report/metrics/BuildAttribute.kt

@@ -18,9 +18,11 @@ enum class BuildAttributeKind : Serializable {
 enum class BuildAttribute(val kind: BuildAttributeKind, val readableString: String) : Serializable {
     NO_BUILD_HISTORY(BuildAttributeKind.REBUILD_REASON, "Build history file not found"),
     NO_ABI_SNAPSHOT(BuildAttributeKind.REBUILD_REASON, "ABI snapshot not found"),
-    INTERNAL_ERROR(BuildAttributeKind.REBUILD_REASON, "Internal error during preparation of IC round"),
     CLASSPATH_SNAPSHOT_NOT_FOUND(BuildAttributeKind.REBUILD_REASON, "Classpath snapshot not found"),
-    INCREMENTAL_COMPILATION_FAILED(BuildAttributeKind.REBUILD_REASON, "Incremental compilation failed"),
+    IC_FAILED_TO_GET_CHANGED_FILES(BuildAttributeKind.REBUILD_REASON, "Failed to get changed files"),
+    IC_FAILED_TO_COMPUTE_FILES_TO_RECOMPILE(BuildAttributeKind.REBUILD_REASON, "Failed to compute files to recompile"),
+    IC_FAILED_TO_COMPILE_INCREMENTALLY(BuildAttributeKind.REBUILD_REASON, "Failed to compile incrementally"),
+    IC_FAILED_TO_CLOSE_CACHES(BuildAttributeKind.REBUILD_REASON, "Failed to close caches"),
     UNKNOWN_CHANGES_IN_GRADLE_INPUTS(BuildAttributeKind.REBUILD_REASON, "Unknown Gradle changes"),
     JAVA_CHANGE_UNTRACKED_FILE_IS_REMOVED(BuildAttributeKind.REBUILD_REASON, "Untracked Java file is removed"),
     JAVA_CHANGE_UNEXPECTED_PSI(BuildAttributeKind.REBUILD_REASON, "Java PSI file is expected"),

build-common/src/org/jetbrains/kotlin/incremental/fileUtils.kt

@@ -29,15 +29,15 @@ fun File.isClassFile(): Boolean =
         extension.equals("class", ignoreCase = true)
 
 /**
- * Deletes the contents of this directory (not the directory itself) if it exists, or creates the directory if it does not yet exist.
+ * Deletes the contents of this directory (not the directory itself).
  *
- * If this is a regular file, this method will throw an exception.
+ * If the directory does not exist or if this is a regular file, this method will throw an exception.
  */
-fun File.cleanDirectoryContents() {
+fun File.deleteDirectoryContents() {
     when {
         isDirectory -> listFiles()!!.forEach { it.deleteRecursivelyOrThrow() }
-        isFile -> error("File.cleanDirectoryContents does not accept a regular file: $path")
-        else -> mkdirsOrThrow()
+        isFile -> error("Expected a directory but found a regular file: $path")
+        else -> error("Directory does not exist: $path")
     }
 }
 
@@ -49,11 +49,12 @@ fun File.deleteRecursivelyOrThrow() {
 }
 
 /**
- * Creates this directory (if it does not yet exist), throwing an exception if the directiory creation failed or if a regular file already
- * exists at this path.
+ * Creates this directory (if it does not yet exist).
+ *
+ * If a regular file already exists at this path, this method will throw an exception.
  */
 @Suppress("SpellCheckingInspection")
-fun File.mkdirsOrThrow() {
+fun File.createDirectory() {
     when {
         isDirectory -> Unit
         isFile -> error("A regular file already exists at this path: $path")