Previously, the transitory state only needed and valid during
generation of the LLVM IR for the function body was conflated
with the general codegen metadata for the function declaration
in IrFunction.
There is further potential for cleanup regarding the use of
gIR->func() and so on all over the code base, but this is out
of scope of this commit, which is only concerned with those
IrFunction members moved to FuncGenState.
GitHub: Fixes#1661.
When certain attributes are applied to the calling function, like "unsafe-fp-math", the inlined inlineIR function has to have the same attributes otherwise the calling function attribute will be reset to the safe merge of the two: "false". Because the same inlineIR function can be called in different functions using an alias definition, a new function (with possibly different attributes) has to be instantiated upon every call.
Related GH issue #1438
Starting with LLVM 3.7, linkage and COMDAT are 2 different concepts.
This means that LinkageODROnce does not put the object into a COMDAT.
On Windows this resulted in linker error messages.
This PR places all template functions, TypeInfo objects and other
objects into a COMDAT.
