[llvm-symbolizer] Print file/line for a PC even if there is no DIE describing it.

This is important for symbolizing executables with debug info in
unavailable .dwo files. Even if all DIE entries are missing, we can
still symbolize an address: function name can be fetched from symbol table,
and file/line info can be fetched from line table.

llvm-svn: 206665
diff --git a/llvm/test/DebugInfo/Inputs/llvm-symbolizer-dwo-test.cc b/llvm/test/DebugInfo/Inputs/llvm-symbolizer-dwo-test.cc
new file mode 100644
index 0000000..ea0967a
--- /dev/null
+++ b/llvm/test/DebugInfo/Inputs/llvm-symbolizer-dwo-test.cc
@@ -0,0 +1,18 @@
+int f(int a, int b) {
+  return a + b;
+}
+
+int g(int a) {
+  return a + 1;
+}
+
+
+int main() {
+  return f(2, g(2));
+}
+
+// Built with Clang 3.5.0:
+// $ mkdir -p /tmp/dbginfo
+// $ cp llvm-symbolizer-dwo-test.cc /tmp/dbginfo
+// $ cd /tmp/dbginfo
+// $ clang -gsplit-dwarf llvm-symbolizer-dwo-test.cc