Add test case for MIR inlining debuginfo line numbers

Author: wesleywiser

src/test/codegen/mir-inlined-line-numbers.rs

@@ -0,0 +1,25 @@
+// compile-flags: -O -g
+
+#![crate_type = "lib"]
+
+#[inline(always)]
+fn foo() {
+    bar();
+}
+
+#[inline(never)]
+#[no_mangle]
+fn bar() {
+    panic!();
+}
+
+#[no_mangle]
+pub fn example() {
+    foo();
+}
+
+// CHECK-LABEL: @example
+// CHECK:   tail call void @bar(), !dbg [[DBG_ID:![0-9]+]]
+// CHECK: [[DBG_ID]] = !DILocation(line: 18, 
+// CHECK-SAME:                     inlinedAt: [[INLINE_ID:![0-9]+]])
+// CHECK: [[INLINE_ID]] = !DILocation(line: 18,