using import_name in wasm32 target causes undefined symbols if it matches a builtin

[lesleyrs]

little example: https://github.com/lesleyrs/builtin-fail

When there are 2 symbols available (builtin and import_name) it unexpectedly causes undefined symbol linking error.

There's no great workaround for this, because the existing builtins change per clang version, so if you decided to do specific -fno-builtin-xxx that could fail to compile on newer clang versions.

I think it's best for builtin to just override the import_name the same way that builtins override other funcs, especially since the builtin math funcs only appear when math.h is included. (I'm importing math funcs from JS)

[llvmbot]

@llvm/issue-subscribers-backend-webassembly

Author: None (lesleyrs)

little example: https://github.com/lesleyrs/builtin-fail

When there are 2 symbols available (builtin and import_name) it unexpectedly causes undefined symbol linking error.

There's no great workaround for this, because the existing builtins change per clang version, so if you decided to do specific -fno-builtin-xxx that could fail to compile on newer clang versions.

I think it's best for builtin to just override the import_name the same way that builtins override other funcs, especially since the builtin math funcs only appear when math.h is included. (I'm importing math funcs from JS)