Support libcorkscrew on x86 hosts in binaries using glibc.

Change-Id: I1f2b7f21cc7f8227dbe7d294fed88cb691a24d09
diff --git a/libcorkscrew/test.c b/libcorkscrew/test.c
new file mode 100644
index 0000000..2d1ba7c
--- /dev/null
+++ b/libcorkscrew/test.c
@@ -0,0 +1,42 @@
+#include <corkscrew/backtrace.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void do_backtrace() {
+  const size_t MAX_DEPTH = 32;
+  backtrace_frame_t* frames = (backtrace_frame_t*) malloc(sizeof(backtrace_frame_t) * MAX_DEPTH);
+  ssize_t frame_count = unwind_backtrace(frames, 0, MAX_DEPTH);
+  fprintf(stderr, "frame_count=%d\n", (int) frame_count);
+
+  backtrace_symbol_t* backtrace_symbols = (backtrace_symbol_t*) malloc(sizeof(backtrace_symbol_t) * frame_count);
+  get_backtrace_symbols(frames, frame_count, backtrace_symbols);
+
+  for (size_t i = 0; i < (size_t) frame_count; ++i) {
+    char line[MAX_BACKTRACE_LINE_LENGTH];
+    format_backtrace_line(i, &frames[i], &backtrace_symbols[i],
+                          line, MAX_BACKTRACE_LINE_LENGTH);
+    fprintf(stderr, "  %s\n", line);
+  }
+
+  free_backtrace_symbols(backtrace_symbols, frame_count);
+  free(backtrace_symbols);
+  free(frames);
+}
+
+__attribute__ ((noinline)) void g() {
+  fprintf(stderr, "g()\n");
+  do_backtrace();
+}
+
+__attribute__ ((noinline)) int f(int i) {
+  fprintf(stderr, "f(%i)\n", i);
+  if (i == 0) {
+    g();
+    return 0;
+  }
+  return f(i - 1);
+}
+
+int main() {
+  return f(5);
+}