Minor: report error instead of crash with exceptions when collect JetFiles to compile and remove obsolete (wrong now) code

#EA-61681 Obsolete

compiler/testData/cli/jvm/nonexistentPathInModule.args

@@ -0,0 +1,2 @@
+-module
+$TESTDATA_DIR$/nonexistentPathInModule.xml

compiler/testData/cli/jvm/nonexistentPathInModule.out

@@ -0,0 +1,3 @@
+error: source file or directory not found: $TESTDATA_DIR$/nonexistentFile.kt
+error: source file or directory not found: $TESTDATA_DIR$/some/nonexistent/dir
+COMPILATION_ERROR

compiler/testData/cli/jvm/nonexistentPathInModule.xml

@@ -0,0 +1,6 @@
+<modules>
+    <module name="name" outputDir="whatever" type="java-production">
+        <sources path="nonexistentFile.kt"/>
+        <sources path="some/nonexistent/dir/"/>
+    </module>
+</modules>

compiler/testData/cli/jvm/nonexistentScript.args

@@ -0,0 +1,2 @@
+-script
+path/to/nonexistent.kts

compiler/testData/cli/jvm/nonexistentScript.out

@@ -0,0 +1,2 @@
+error: source file or directory not found: path/to/nonexistent.kts
+COMPILATION_ERROR