Provide a generic fallback for pg_compiler_barrier using an extern function.
If the compiler/arch combination does not provide compiler barriers,
provide a fallback. That fallback simply consists out of a function
call into a externally defined function. That should guarantee
compiler barrierer s
Fix alignment of pg_atomic_uint64 variables on some 32bit platforms.
I failed to recognize that pg_atomic_uint64 wasn't guaranteed to be 8
byte aligned on some 32bit platforms - which it has to be on some
platforms to guarantee the desired atomicity and which we assert.
As this is all compiler sp
