This rewrites the whole relocation parsing to work properly.
* we no longer use LocalRelocation and simply assign a new SectionIndex as new sections are encountered.
* we no longer use string matching to determine what function applies relocations to what, instead we use the field in the elf section header that tells us
* we no longer merge sections, each section from every function is preserved as an independent custom section in the module.
* we now discover any new sections that need to be pulled in recursively as we parse each section
* many error cases are either handled, or report CompileErrors.
In order to work with spectests, we need to change our function types to include a second fixed parameter, there are now two vmctx's (callee and caller) before any other arguments. Because we have a uniform call sequence for imported and local function calls (which we must have because we store both in the table and don't store what kind it is), we need to change the llvm function types for all our own functions and update how we call them and how we find our own arguments.
This updates to a newer inkwell to pick up a fix to Section::get_contents. Picking that up changed builder.build_struct_gep to return a Result, and there's many API updates scattered around to support that.
Compute the function names for all local and imported functions in the module in advance and pass that mapping to the function code generation.
debug_trap is added to Intrinsics, though all users are commented out.
Turning an LLVM module into a CompiledFunction should be refactored.
Bump to latest inkwell so that we can make use of object_file with the fixes.
Comment out accidentally committed debug code that writes to my home directory.
Start filling in the code to generate trampolines. Move func_type_to_llvm and type_to_llvm from code.rs to intrinsics.rs so that trampoline code can reuse them.
