Fixed issue with run-r8-on-gmscore v4 tripping an assert by adding conservative bailout for inlining.

BUG=

Change-Id: I8c52c1166f15e6d77dfbaedd14f8d547958fd058
diff --git a/src/main/java/com/android/tools/r8/ir/optimize/Inliner.java b/src/main/java/com/android/tools/r8/ir/optimize/Inliner.java
index dc2ed67..11548bc 100644
--- a/src/main/java/com/android/tools/r8/ir/optimize/Inliner.java
+++ b/src/main/java/com/android/tools/r8/ir/optimize/Inliner.java
@@ -223,7 +223,10 @@
           InlineAction result = invoke.computeInlining(oracle);
           if (result != null) {
             DexEncodedMethod target = appInfo.lookup(invoke.getType(), invoke.getInvokedMethod());
-            assert target != null;
+            if (target == null) {
+              // The declared target cannot be found so skip inlining.
+              continue;
+            }
             boolean forceInline = target.getOptimizationInfo().forceInline();
             if (!target.isProcessed() && !forceInline) {
               // Do not inline code that was not processed unless we have to force inline.