Hard-code `-parameters` and `-source 8 -target 8` in javac-turbine

This makes its behaviour consistent with regular turbine, avoiding
skew when switching between implementations.

--
MOS_MIGRATED_REVID=140547517

src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbine.java

diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbine.java b/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbine.java
index 5934676..b9b323d 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbine.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbine.java
@@ -135,6 +135,15 @@
     // Disable debug info
     argbuilder.add("-g:none");
 
+    // Enable MethodParameters
+    argbuilder.add("-parameters");
+
+    // Compile-time jars always use Java 8
+    argbuilder.add("-source");
+    argbuilder.add("8");
+    argbuilder.add("-source");
+    argbuilder.add("8");
+
     ImmutableList<Path> processorpath;
     if (!turbineOptions.processors().isEmpty()) {
       argbuilder.add("-processor");

src/java_tools/buildjar/javatests/com/google/devtools/build/java/turbine/javac/JavacTurbineTest.java

diff --git a/src/java_tools/buildjar/javatests/com/google/devtools/build/java/turbine/javac/JavacTurbineTest.java b/src/java_tools/buildjar/javatests/com/google/devtools/build/java/turbine/javac/JavacTurbineTest.java
index 30c8e13..7a248c4 100644
--- a/src/java_tools/buildjar/javatests/com/google/devtools/build/java/turbine/javac/JavacTurbineTest.java
+++ b/src/java_tools/buildjar/javatests/com/google/devtools/build/java/turbine/javac/JavacTurbineTest.java
@@ -170,6 +170,7 @@
       "",
       "  // access flags 0x9",
       "  public static main([Ljava/lang/String;)V",
+      "    // parameter  args",
       "}",
       ""
     };
@@ -316,6 +317,7 @@
         "",
         "  // access flags 0x9",
         "  public static main([Ljava/lang/String;)V",
+        "    // parameter  args",
         "}",
         ""
       };
@@ -753,6 +755,7 @@
       "",
       "  // access flags 0x9",
       "  public static valueOf(Ljava/lang/String;)LTheEnum;",
+      "    // parameter mandated  name",
       "}",
       ""
     };
@@ -1350,6 +1353,7 @@
       "",
       "  // access flags 0x9",
       "  public static valueOf(Ljava/lang/String;)LP;",
+      "    // parameter mandated  name",
       "}",
       ""
     };
@@ -1392,6 +1396,7 @@
       "",
       "  // access flags 0x9",
       "  public static valueOf(Ljava/lang/String;)LP;",
+      "    // parameter mandated  name",
       "}",
       ""
     };