Recognize '**' as alias for '^'

com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/ops/BinaryArithmetic.java

@@ -68,7 +68,7 @@ public abstract class BinaryArithmetic extends Operation {
     public static class MultiplyBuiltin {
     }
 
-    @RBuiltin(name = "^", kind = PRIMITIVE, parameterNames = {"", ""}, alwaysSplit = true, dispatch = OPS_GROUP_GENERIC, behavior = PURE_ARITHMETIC)
+    @RBuiltin(name = "^", aliases = "**", kind = PRIMITIVE, parameterNames = {"", ""}, alwaysSplit = true, dispatch = OPS_GROUP_GENERIC, behavior = PURE_ARITHMETIC)
     public static class PowBuiltin {
     }
 

com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/ExpectedTestOutput.test

@@ -85980,6 +85980,10 @@ Error in x + y : non-conformable arrays
 #{ x <- 1:2 ; dim(x) <- 1:2 ; y <- 2:3 ; dim(y) <- c(1,1,2) ; x + y }
 Error in x + y : non-conformable arrays
+##com.oracle.truffle.r.test.library.base.TestSimpleArithmetic.testVectorsOperations#
+#3 ** 4
+[1] 81
+
 ##com.oracle.truffle.r.test.library.base.TestSimpleArithmetic.testVectorsOperations#
 #{ -2:2 / 0:0 }
 [1] -Inf -Inf  NaN  Inf  Inf

com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/library/base/TestSimpleArithmetic.java

@@ -288,6 +288,7 @@ public class TestSimpleArithmetic extends TestBase {
         assertEval("{ c(1,3) / c(2,4) }");
         assertEval("{ 1:1 / 0:0 }");
         assertEval("{ -2:2 / 0:0 }");
+        assertEval("3 ** 4");
     }
 
     @Test