Re: JIT compiling with LLVM v10.0

Hi,

I've pushed v10.0. The big (and pretty painful to make) change is that
now all the LLVM specific code lives in src/backend/jit/llvm, which is
built as a shared library which is loaded on demand.

The layout is now as follows:

src/backend/jit/jit.c:
    Part of JITing always linked into the server. Supports loading the
    LLVM using JIT library.

src/backend/jit/llvm/
Infrastructure:
 llvmjit.c:
    General code generation and optimization infrastructure
 llvmjit_error.cpp, llvmjit_wrap.cpp:
    Error / backward compat wrappers
 llvmjit_inline.cpp:
    Cross module inlining support
Code-Gen:
  llvmjit_expr.c
    Expression compilation
  llvmjit_deform.c
    Deform compilation

I generally like how this shaped out. There's a good amount of followup
cleanup needed, but I'd appreciate some early feedback.


I've also rebased onto a recent master version.

postgres[21915][1]=# SELECT pg_llvmjit_available();
┌──────────────────────┐
│ pg_llvmjit_available │
├──────────────────────┤
│ t                    │
└──────────────────────┘
(1 row)

make -C src/backend/jit/llvm/ uninstall
postgres[21915][1]=# \c
You are now connected to database "postgres" as user "andres".
postgres[21922][1]=# SELECT pg_llvmjit_available();
┌──────────────────────┐
│ pg_llvmjit_available │
├──────────────────────┤
│ f                    │
└──────────────────────┘
(1 row)

Yeha ;)

Greetings,

Andres Freund