This has the benefit of not requiring a 'runtime' IR file, so that
complete relocatable files can be built without requiring input IR.
This makes the compiler a lot easier to use without the Makefile.
Code size is not affected.
This commit moves the itfmethod call implemented directly in LLVM IR to
a Go implementation in the runtime. Additionally, it fixes variable
names to be more obvious and adds a lot of documentation to explain how
interfaces actually work in TinyGo.
Code size changes for src/examples/hello:
nrf: -144
unix: -93
I'm guessing this code size reduction is a result of removing the
'noinline' function attribute.
This is a big combined change. Other changes in this commit:
* Analyze makeinterface and make sure type switches don't include
unnecessary cases.
* Do not include CGo wrapper functions in the analyzer callgraph.
This also avoids some unnecessary type IDs.
* Give all Go named structs a name in LLVM.
* Use such a named struct for compiler-generated task data.
* Use the type and function names defined by the ssa and types
package instead of generating our own.
* Some improvements to function pointers.
* A few other minor improvements.
The one thing lacking here is interface-to-interface assertions.
