Set linker_is_gnu.

Author: reitermarkus

src/librustc_target/spec/xtensa_esp32_none_elf.rs

@@ -18,6 +18,7 @@ pub fn target() -> TargetResult {
             target_family: Some("unix".to_string()),
             cpu: "esp32".to_string(),
             linker: Some("xtensa-esp32-elf-gcc".to_string()),
+            linker_is_gnu: true,
 
             max_atomic_width: Some(32),
 

src/librustc_target/spec/xtensa_esp8266_none_elf.rs

@@ -18,6 +18,7 @@ pub fn target() -> TargetResult {
             target_family: Some("unix".to_string()),
             cpu: "esp8266".to_string(),
             linker: Some("xtensa-lx106-elf-gcc".to_string()),
+            linker_is_gnu: true,
 
             max_atomic_width: Some(32),