Don't pass -fPIC by default on wasm (#1245)

* Don't pass -fPIC by default on wasm

Fix #1240

* Fix cargo fmt

Author: NobodyXu

src/lib.rs

@@ -1996,12 +1996,13 @@ impl Build {
                     cmd.push_cc_arg("-fdata-sections".into());
                 }
                 // Disable generation of PIC on bare-metal for now: rust-lld doesn't support this yet
-                if self.pic.unwrap_or(
+                if self.pic.unwrap_or_else(|| {
                     !target.contains("windows")
                         && !target.contains("-none-")
                         && !target.ends_with("-none")
-                        && !target.contains("uefi"),
-                ) {
+                        && !target.contains("uefi")
+                        && !Build::is_wasi_target(target)
+                }) {
                     cmd.push_cc_arg("-fPIC".into());
                     // PLT only applies if code is compiled with PIC support,
                     // and only for ELF targets.