Track LLVM 14 API changes, up to 2022-01-30.

Tested with LLVM 11, LLVM 13 and LLVM's main branch at commit
8d8fce87bbd5.  There are still some deprecation warnings that will need
to be sorted out, but this may be enough to turn "seawasp" green again.

Like commit e6a76002, done on master only for now.

Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA%2BhUKG%2B3Ac3He9_SpJcxeiiVknbcES1tbZEkH9sRBdJFGj8K5Q%40mail.gmail.com

src/backend/jit/llvm/llvmjit_error.cpp

@@ -23,15 +23,22 @@ extern "C"
 
 #include "jit/llvmjit.h"
 
+#include <new>
 
 static int fatal_new_handler_depth = 0;
 static std::new_handler old_new_handler = NULL;
 
 static void fatal_system_new_handler(void);
 #if LLVM_VERSION_MAJOR > 4
+static void fatal_llvm_new_handler(void *user_data, const char *reason, bool gen_crash_diag);
+#if LLVM_VERSION_MAJOR < 14
 static void fatal_llvm_new_handler(void *user_data, const std::string& reason, bool gen_crash_diag);
 #endif
+#endif
+static void fatal_llvm_error_handler(void *user_data, const char *reason, bool gen_crash_diag);
+#if LLVM_VERSION_MAJOR < 14
 static void fatal_llvm_error_handler(void *user_data, const std::string& reason, bool gen_crash_diag);
+#endif
 
 
 /*
@@ -129,23 +136,41 @@ fatal_system_new_handler(void)
 #if LLVM_VERSION_MAJOR > 4
 static void
 fatal_llvm_new_handler(void *user_data,
-					   const std::string& reason,
+					   const char *reason,
 					   bool gen_crash_diag)
 {
 	ereport(FATAL,
 			(errcode(ERRCODE_OUT_OF_MEMORY),
 			 errmsg("out of memory"),
-			 errdetail("While in LLVM: %s", reason.c_str())));
+			 errdetail("While in LLVM: %s", reason)));
+}
+#if LLVM_VERSION_MAJOR < 14
+static void
+fatal_llvm_new_handler(void *user_data,
+					   const std::string& reason,
+					   bool gen_crash_diag)
+{
+	fatal_llvm_new_handler(user_data, reason.c_str(), gen_crash_diag);
 }
 #endif
+#endif
 
 static void
 fatal_llvm_error_handler(void *user_data,
-						 const std::string& reason,
+						 const char *reason,
 						 bool gen_crash_diag)
 {
 	ereport(FATAL,
 			(errcode(ERRCODE_OUT_OF_MEMORY),
-			 errmsg("fatal llvm error: %s",
-					reason.c_str())));
+			 errmsg("fatal llvm error: %s", reason)));
 }
+
+#if LLVM_VERSION_MAJOR < 14
+static void
+fatal_llvm_error_handler(void *user_data,
+						 const std::string& reason,
+						 bool gen_crash_diag)
+{
+	fatal_llvm_error_handler(user_data, reason.c_str(), gen_crash_diag);
+}
+#endif