Try to guess symbol address in Wasm

[ia0]

I would suggest trying to guess an address for exported globals in Wasm instead of always using 0.

At least in Rust, it looks like symbols are exported globals of type i32 which value is the address (in linear memory) of the symbol. For example, an empty wasm module in Rust looks like:

(module
 (global $__stack_pointer (mut i32) (i32.const 1048576))
 (global $global$1 i32 (i32.const 1048576))
 (global $global$2 i32 (i32.const 1048576))
 (memory $0 16)
 (export "memory" (memory $0))
 (export "__data_end" (global $global$1))
 (export "__heap_base" (global $global$2))
 ;; features section: mutable-globals, sign-ext
)

Notice how __data_end and __heap_base are exported globals of type i32 with a value in linear memory (after the initial stack pointer).

My suggestion would be to detect those cases and fill the symbol address with the global value instead of 0. I wrote a draft PR in case the idea is not rejected.