Index: utils/extract_symbols.py
===================================================================
--- utils/extract_symbols.py
+++ utils/extract_symbols.py
@@ -128,8 +128,15 @@
             if match:
                 return match.group(1)
         return symbol
-    # Function template instantiations start with ?$, discard them as it's
-    # assumed that the definition is public
+    # Function template instantiations start with ?$, keep the explicit
+    # specializations of clang::Type::getAs for clang::AttributedType,
+    # clang::TemplateSpecializationType, and clang::TypedefType that are defined
+    # in clang's lib/AST/Type.cpp; discard the rest as it's assumed that the
+    # definition is public
+    elif symbol == '??$getAs@VAttributedType@clang@@@Type@clang@@QEBAPEBVAttributedType@1@XZ' \
+         or symbol == '??$getAs@VTemplateSpecializationType@clang@@@Type@clang@@QEBAPEBVTemplateSpecializationType@1@XZ' \
+         or symbol == '??$getAs@VTypedefType@clang@@@Type@clang@@QEBAPEBVTypedefType@1@XZ':
+        return symbol
     elif symbol.startswith('??$'):
         return None
     # Deleting destructors start with ?_G or ?_E and can be discarded because
@@ -195,8 +202,15 @@
     # defined in headers and not required to be kept
     if re.match('[CD][123]', names[-1][0]) and names[-2][1]:
         return None
-    # Discard function template instantiations as it's assumed that the
+    # Keep the explicit specializations of clang::Type::getAs for
+    # clang::AttributedType, clang::TemplateSpecializationType, and
+    # clang::TypedefType that are defined in clang's lib/AST/Type.cpp; discard
+    # any other function template instantiations as it's assumed that the
     # definition is public
+    elif symbol == '_ZNK5clang4Type5getAsINS_14AttributedTypeEEEPKT_v' \
+         or symbol == '_ZNK5clang4Type5getAsINS_26TemplateSpecializationTypeEEEPKT_v' \
+         or symbol == '_ZNK5clang4Type5getAsINS_11TypedefTypeEEEPKT_v':
+        return symbol
     elif names[-1][1]:
         return None
     # Keep llvm:: and clang:: names