Add gdb macro to find assertion scopes on the stack.

This is how it would look like.

(gdb) bta
[1 ] V8_Fatal                                         ../../src/base/logging.cc:67
[2 ] v8::internal::Heap::AllocateRaw                  ../../src/heap/heap-inl.h:298
[3 ] v8::internal::Heap::AllocateHeapNumber           ../../src/heap/heap.cc:2432
[4 ] v8::internal::Factory::NewHeapNumber             ../../src/factory.cc:1253
[5 ] v8::internal::Factory::NewNumber                 ../../src/factory.cc:1228
[6 ] v8::internal::__RT_impl_Runtime_ConstructDouble  ../../src/runtime/runtime-test.cc:32
 -> Allow HEAP_ALLOCATION (yes_gc)
 -> Disallow HEAP_ALLOCATION (no_gc)
[7 ] v8::internal::Runtime_ConstructDouble            ../../src/runtime/runtime-test.cc:24

R=jochen@chromium.org

Review-Url: https://codereview.chromium.org/2466263007
Cr-Commit-Position: refs/heads/master@{#40748}

tools/gdbinit

@@ -68,5 +68,31 @@ Skip the jitted stack on x64 to where we entered JS last.
 Usage: jss
 end
 
+# Print stack trace with assertion scopes.
+define bta
+python
+import re
+frame_re = re.compile("^#(\d+).* in (\S+) .+ at (.+)")
+assert_re = re.compile("^\s*(\S+) = .+<v8::internal::Per\w+AssertType::(\w+)_ASSERT, (false|true)>")
+btl = gdb.execute("backtrace full", to_string = True).splitlines()
+for l in btl:
+  match = frame_re.match(l)
+  if match:
+    print("[%-2s] %-60s %-40s" % (match.group(1), match.group(2), match.group(3)))
+  match = assert_re.match(l)
+  if match:
+    if match.group(3) == "false":
+      prefix = "Disallow"
+      color = "\033[91m"
+    else:
+      prefix = "Allow"
+      color = "\033[92m"
+    print("%s -> %s %s (%s)\033[0m" % (color, prefix, match.group(2), match.group(1)))
+end
+document bta
+Print stack trace with assertion scopes
+Usage: bta
+end
+
 set disassembly-flavor intel
 set disable-randomization off