Stop ignoring some unit tests

(cherry picked from commit fb99907)

Author: Pavel Marek

com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_gsub.java

@@ -245,9 +245,8 @@ public void testGsubPCRE() {
         // Tests with UTF-8 strings
         assertEval("{ gsub(pattern = 'a*', replacement = 'x', x = 'ÄaÄ', perl = TRUE) }");
         assertEval("{ gsub(pattern = 'a*', replacement = 'x', x = 'ÄaaaaÄ', perl = TRUE) }");
-        assertEval(Ignored.ImplementationError, "{ gsub(pattern = 'Ä*', replacement = 'x', x = 'aÄÄÄÄÄb', perl = TRUE) }");
+        assertEval("{ gsub(pattern = 'Ä*', replacement = 'x', x = 'aÄÄÄÄÄb', perl = TRUE) }");
 
-        // FIXME: Enable once unicode support is implemented.
-        assertEval(Ignored.ImplementationError, "{ gsub('([⚽])', '\\\\1', '─', perl=TRUE)} ");
+        assertEval("{ gsub('([⚽])', '\\\\1', '─', perl=TRUE)} ");
     }
 }

com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_strsplit.java

@@ -177,6 +177,6 @@ public void testStrSplit() {
         // This test is ignored because it is a special case with an empty match at the beginning
         // and positive and negative lookarounds. Empty match at the beginning is normally
         // replaced by an empty character vector, but in this case gnur does not do that.
-        assertEval(Ignored.ImplementationError, "strsplit('/some/path/to/somewhere' , '^(?=/)(?!//)|(?<!^)(?<!^/)/', perl = TRUE)");
+        assertEval("strsplit('/some/path/to/somewhere' , '^(?=/)(?!//)|(?<!^)(?<!^/)/', perl = TRUE)");
     }
 }

com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_sub.java

@@ -167,9 +167,8 @@ public void testSub() {
         assertEval("{ sub(pattern = 'a*', replacement = 'x', x = 'ÄaÄ', perl = TRUE) }");
         assertEval("{ sub(pattern = 'a*', replacement = 'x', x = 'ÄaaaaÄ', perl = TRUE) }");
 
-        // FIXME
         // Expected output: [1] "xaÄÄÄÄÄb"
         // FastR output: [1] "axÄÄÄÄb"
-        assertEval(Ignored.ImplementationError, "{ sub(pattern = 'Ä*', replacement = 'x', x = 'aÄÄÄÄÄb', perl = TRUE) }");
+        assertEval("{ sub(pattern = 'Ä*', replacement = 'x', x = 'aÄÄÄÄÄb', perl = TRUE) }");
     }
 }