Add support for symbols with {lambda...#1} to merge_libraries.py (#1279)

* Add support for symbols like this one, which is referenced by the Firestore iOS SDK on Linux:
grpc_slice_malloc_large::{lambda(grpc_slice_refcount*)#1}::_FUN(grpc_slice_refcount*)

* Handle #.

* Add the latest {lambda...#1} case to the test.

Author: jonsimantov

scripts/merge_libraries.py

@@ -418,7 +418,7 @@ def get_top_level_namespaces(demangled_symbols):
   # It will specifically not match second-level or deeper namespaces:
   #   matched_namespace::unmatched_namespace::Class::Method()
   regex_top_level_namespaces = re.compile(
-      r"(?<![a-zA-Z0-9_])(?<!::)([a-zA-Z_~\$][a-zA-Z0-9_]*)::(?=[a-zA-Z_~` \$])")
+      r"(?<![a-zA-Z0-9_])(?<!::)([a-zA-Z_~\{\$][a-zA-Z0-9_\{\}\#]*)::(?=[a-zA-Z_~` \{\$])")
   found_namespaces = set()
   for cppsymbol in demangled_symbols:
     m = regex_top_level_namespaces.findall(cppsymbol)

scripts/merge_libraries_test.py

@@ -51,9 +51,13 @@ def test_get_top_level_namespaces(self):
         "topleveldestructor::~topleveldestructor()": {"topleveldestructor"},
         "rtti::RttiClass::`RTTI Class Hierarchy Descriptor'": {"rtti"},
         "toplevelrtti::`RTTI Class Hierarchy Descriptor'": {"toplevelrtti"},
+        # Test some complicated grpc cases that required special handling.
         "public: virtual enum grpc_security_level __cdecl grpc_call_credentials::min_security_level(void) const": {
           "grpc_call_credentials"
         },
+        "grpc_slice_malloc_large::{lambda(grpc_slice_refcount*)#1}::_FUN(grpc_slice_refcount*)": {
+          "grpc_slice_malloc_large"
+        },
         # std namespaces are used by get_top_level_namespaces but not by add_automatic_namespaces
         "std::dont_use_this<std::other_thing>()": {"std"},
         "std::vector<inside_std_template_param::class>()": { "std", "inside_std_template_param" }