Add a test that without debuginfo symbols still resolve

Almost all platforms should still have some degree of symbolication
without debug symbols being present (aka the dynamic symbol table and
such), so add a test asserting that symbols do indeed come out in these
scenarios.

This test will likely need to be blacklisted for platforms over time,
but that's ok.

Author: alexcrichton

ci/azure-test-all.yml

@@ -3,7 +3,7 @@ steps:
     submodules: true
   - template: azure-install-rust.yml
 
-  - bash: cargo build --manifest-path backtrace-sys/Cargo.toml
+  - bash: cargo build --manifest-path crates/backtrace-sys/Cargo.toml
     displayName: "Build backtrace-sys"
   - bash: cargo build
     displayName: "Build backtrace"

crates/without_debuginfo/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "without_debuginfo"
+version = "0.1.0"
+authors = ["Alex Crichton <[email protected]>"]
+edition = "2018"
+
+[dependencies]
+backtrace = { path = "../.." }
+
+[profile.dev]
+debug = false
+
+[profile.test]
+debug = false

crates/without_debuginfo/src/lib.rs

@@ -0,0 +1 @@
+// intentionally blank

crates/without_debuginfo/tests/smoke.rs

@@ -0,0 +1,19 @@
+#[test]
+fn all_frames_have_symbols() {
+    println!("{:?}", backtrace::Backtrace::new());
+
+    let mut all_have_symbols = true;
+    backtrace::trace(|frame| {
+        let mut any = false;
+        backtrace::resolve_frame(frame, |sym| {
+            if sym.name().is_some() {
+                any = true;
+            }
+        });
+        if !any && !frame.ip().is_null() {
+            all_have_symbols = false;
+        }
+        true
+    });
+    assert!(all_have_symbols);
+}