force UTF-8 for slurp and write

Author: Martijn Hoekstra

test/test/CompilerTest.scala

@@ -452,7 +452,18 @@ abstract class CompilerTest {
     processFileDir(sourceFile, { sf =>
       if (extensionsToCopy.contains(sf.extension)) {
         dest.parent.jfile.mkdirs
-        dest.toFile.writeAll(s"/* !!!!! WARNING: DO NOT MODIFY. Original is at: $sf !!!!! */", sf.slurp)
+        try {
+        scala.reflect.io.File(dest)(scala.io.Codec.UTF8).writeAll(s"/* !!!!! WARNING: DO NOT MODIFY. Original is at: $sf !!!!! */", sf.slurp("UTF-8"))
+        } catch {
+          case unmappable: java.nio.charset.UnmappableCharacterException => {
+            log(s"ERROR: reading file $sf failed to decode: $unmappable")
+            throw unmappable
+          }
+          case t: Throwable => {
+            log(s"ERROR: file $sf failed for some other reason: $t")
+            throw t
+          }
+        }
       } else {
         log(s"WARNING: ignoring $sf")
       }