Ignore trailing empty lines in benchmark dump parser

The new split in string utils does not handle trailing empty lines
like String.split

Change-Id: I8501e9bea2ea86a4e7303e133b4242a288f7dd36
diff --git a/src/main/java/com/android/tools/r8/dump/DumpOptions.java b/src/main/java/com/android/tools/r8/dump/DumpOptions.java
index 6d5e880..9779fcf 100644
--- a/src/main/java/com/android/tools/r8/dump/DumpOptions.java
+++ b/src/main/java/com/android/tools/r8/dump/DumpOptions.java
@@ -185,6 +185,9 @@
         '\n',
         line -> {
           String trimmed = line.trim();
+          if (trimmed.isEmpty()) {
+            return;
+          }
           int i = trimmed.indexOf('=');
           if (i < 0) {
             throw new RuntimeException("Invalid dump line. Expected = in line: '" + trimmed + "'");