Basic JIT provider and error handling infrastructure.

This commit introduces:

1) JIT provider abstraction, which allows JIT functionality to be
   implemented in separate shared libraries. That's desirable because
   it allows to install JIT support as a separate package, and because
   it allows experimentation with different forms of JITing.
2) JITContexts which can be, using functions introduced in follow up
   commits, used to emit JITed functions, and have them be cleaned up
   on error.
3) The outline of a LLVM JIT provider, which will be fleshed out in
   subsequent commits.

Documentation for GUCs added, and for JIT in general, will be added in
later commits.

Author: Andres Freund, with architectural input from Jeff Davis
Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de

1 files changed, 2 insertions, 0 deletions

diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 871000b94b..bfc90098f8 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -3371,6 +3371,8 @@ DATA(insert OID = 3935 ( pg_sleep_for			PGNSP PGUID 14 1 0 0 0 f f f t f v s 1 0
 DESCR("sleep for the specified interval");
 DATA(insert OID = 3936 ( pg_sleep_until			PGNSP PGUID 14 1 0 0 0 f f f t f v s 1 0 2278 "1184" _null_ _null_ _null_ _null_ _null_ "select pg_catalog.pg_sleep(extract(epoch from $1) operator(pg_catalog.-) extract(epoch from pg_catalog.clock_timestamp()))" _null_ _null_ _null_ ));
 DESCR("sleep until the specified time");
+DATA(insert OID = 315 (  pg_jit_available	PGNSP PGUID 12 1 0 0 0 f f f t f v s 0 0 16 "" _null_ _null_ _null_ _null_ _null_ pg_jit_available _null_ _null_ _null_ ));
+DESCR("Is JIT compilation available in this session?");
 
 DATA(insert OID = 2971 (  text				PGNSP PGUID 12 1 0 0 0 f f f t f i s 1 0 25 "16" _null_ _null_ _null_ _null_ _null_ booltext _null_ _null_ _null_ ));
 DESCR("convert boolean to text");