Precompiled SPIR-V import support (#5048)

* Precompiled SPIR-V import support

Adds appropriate linkage and function declaration syntax
for SPIR-V functions that are declared, to be imported
from another SPIR-V module.

Unlike DXIL, stripping the Slang IR for a function down
to a declaration requires retaining a block of parameters,
as the function declaration must be emitted to SPIR-V
with the same parameters as a definition. Because that
thwarts the logic in Slang to tell the difference between
a declaration and definition, and explicit decoration is
introduced to explicitly mark functions which need to be
treated as declarations during emit phase.

Fixes #4992

Co-authored-by: Yong He <yonghe@outlook.com>

0 files changed, 0 insertions, 0 deletions