math/or-tools: Fix build with abseil 20230125.0+ and re2 20230601+

Reference:	https://github.com/google/or-tools/issues/3655

math/or-tools/Makefile

@@ -35,6 +35,7 @@ USE_LDCONFIG=	yes
 CMAKE_OFF=	BUILD_PYTHON BUILD_DEPS INSTALL_BUILD_DEPS BUILD_EXAMPLES BUILD_SAMPLES
 CMAKE_ON=	BUILD_CXX
 CMAKE_TESTING_ON=	BUILD_EXAMPLES BUILD_CXX_EXAMPLES
+CXXFLAGS+=	-DABSL_LEGACY_THREAD_ANNOTATIONS
 
 CONFIGURE_ENV=	UNIX_CBC_DIR=${LOCALBASE} UNIX_CLP_DIR=${LOCALBASE}
 

math/or-tools/files/patch-abseil

+--- ortools/lp_data/lp_parser.cc.orig	2022-11-25 09:21:54 UTC
++++ ortools/lp_data/lp_parser.cc
+@@ -185,7 +185,7 @@ bool LPParser::ParseIntegerVariablesList(StringPiece l
+ 
+ bool LPParser::ParseConstraint(StringPiece constraint) {
+   const StatusOr<ParsedConstraint> parsed_constraint_or_status =
+-      ::operations_research::glop::ParseConstraint(constraint.as_string());
++      ::operations_research::glop::ParseConstraint(std::string(constraint));
+   if (!parsed_constraint_or_status.ok()) return false;
+   const ParsedConstraint& parsed_constraint =
+       parsed_constraint_or_status.value();
+@@ -414,7 +414,7 @@ StatusOr<ParsedConstraint> ParseConstraint(absl::strin
+     if (ConsumeToken(&constraint, &consumed_name, &consumed_coeff) !=
+         TokenType::END) {
+       return absl::InvalidArgumentError(absl::StrCat(
+-          "End of input was expected, found: ", constraint.as_string()));
++          "End of input was expected, found: ", std::string(constraint)));
+     }
+   }
+