Check the return of getInteger.

llvm-svn: 281608
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 310392c..e81c685 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -1307,7 +1307,8 @@
     next();
     expect(",");
     uint64_t Val;
-    next().getAsInteger(0, Val);
+    if (next().getAsInteger(0, Val))
+      setError("integer expected");
     expect(")");
     return [=](uint64_t Dot) { return Val; };
   }