std: move FULL_BACKTRACE_DEFAULT to sys::backtrace

Author: joboet

library/std/src/panic.rs

@@ -523,7 +523,7 @@ pub fn get_backtrace_style() -> Option<BacktraceStyle> {
         Some(x) if &x == "0" => BacktraceStyle::Off,
         Some(x) if &x == "full" => BacktraceStyle::Full,
         Some(_) => BacktraceStyle::Short,
-        None if crate::sys::FULL_BACKTRACE_DEFAULT => BacktraceStyle::Full,
+        None if crate::sys::backtrace::FULL_BACKTRACE_DEFAULT => BacktraceStyle::Full,
         None => BacktraceStyle::Off,
     };
 

library/std/src/sys/backtrace.rs

@@ -11,6 +11,12 @@ use crate::{env, fmt, io};
 /// Max number of frames to print.
 const MAX_NB_FRAMES: usize = 100;
 
+pub(crate) const FULL_BACKTRACE_DEFAULT: bool = cfg_select! {
+    // Fuchsia components default to full backtrace.
+    target_os = "fuchsia" => true,
+    _ => false,
+};
+
 pub(crate) struct BacktraceLock<'a>(#[allow(dead_code)] MutexGuard<'a, ()>);
 
 pub(crate) fn lock<'a>() -> BacktraceLock<'a> {

library/std/src/sys/pal/mod.rs

@@ -86,9 +86,3 @@ cfg_select! {
         pub use self::unsupported::*;
     }
 }
-
-pub const FULL_BACKTRACE_DEFAULT: bool = cfg_select! {
-    // Fuchsia components default to full backtrace.
-    target_os = "fuchsia" => true,
-    _ => false,
-};