Set javac encoding to utf-8

Patch by Ariel Weisberg; Reviewed by Jason Brown for CASSANDRA-13466

CHANGES.txt

@@ -1,4 +1,5 @@
 2.1.18
+ * Set javac encoding to utf-8 (CASSANDRA-13466)
  * Fix 2ndary index queries on partition keys for tables with static columns (CASSANDRA-13147)
  * Fix ParseError unhashable type list in cqlsh copy from (CASSANDRA-13364)
  * Log stacktrace of uncaught exceptions (CASSANDRA-13108)

build.xml

@@ -708,6 +708,7 @@
         <!-- Order matters! -->
         <javac fork="true"
                debug="true" debuglevel="${debuglevel}"
+               encoding="utf-8"
                destdir="${build.classes.thrift}" includeantruntime="false" source="${source.version}" target="${target.version}"
                memorymaximumsize="512M">
             <src path="${interface.thrift.dir}/gen-java"/>
@@ -715,6 +716,7 @@
         </javac>
         <javac fork="true"
                debug="true" debuglevel="${debuglevel}"
+               encoding="utf-8"
                destdir="${build.classes.main}" includeantruntime="false" source="${source.version}" target="${target.version}"
                memorymaximumsize="512M">
             <src path="${build.src.java}"/>
@@ -739,7 +741,7 @@
     </path>
     <target name="stress-build" depends="build" description="build stress tool">
     	<mkdir dir="${stress.build.classes}" />
-        <javac debug="true" debuglevel="${debuglevel}" destdir="${stress.build.classes}" includeantruntime="true" source="${source.version}" target="${target.version}">
+        <javac debug="true" debuglevel="${debuglevel}" encoding="utf-8" destdir="${stress.build.classes}" includeantruntime="true" source="${source.version}" target="${target.version}">
             <src path="${stress.build.src}" />
             <classpath>
                 <path refid="cassandra.classes" />
@@ -1072,6 +1074,7 @@
     <javac
      debug="true"
      debuglevel="${debuglevel}"
+     encoding="utf-8"
      destdir="${test.classes}"
      includeantruntime="false"
      source="${source.version}"