Auto merge of #151794 - JonathanBrouwer:rollup-rGbYGX2, r=JonathanBrouwer

Rollup of 12 pull requests

Successful merges:

 - rust-lang/rust#150491 (resolve: Mark items under exported ambiguous imports as exported)
 - rust-lang/rust#150720 (Do not suggest `derive` if there is already an impl)
 - rust-lang/rust#150968 (compiler-builtins: Remove the no-f16-f128 feature)
 - rust-lang/rust#151493 ([RFC] rustc_parse: improve the error diagnostic for "missing let in let chain")
 - rust-lang/rust#151660 (Bump `std`'s `backtrace`'s `rustc-demangle`)
 - rust-lang/rust#151696 (Borrowck: Simplify SCC annotation computation, placeholder rewriting)
 - rust-lang/rust#151704 (Implement `set_output_kind` for Emscripten linker)
 - rust-lang/rust#151706 (Remove Fuchsia from target OS list in unix.rs for sleep)
 - rust-lang/rust#151769 (fix undefined behavior in VecDeque::splice)
 - rust-lang/rust#151779 (stdarch subtree update)
 - rust-lang/rust#151449 ([rustdoc] Add regression test for rust-lang/rust#151411)
 - rust-lang/rust#151773 (clean up checks for constant promotion of integer division/remainder operations)

Author: bors

builtins-shim/Cargo.toml

@@ -47,10 +47,6 @@ c = ["dep:cc"]
 # the generic versions on all platforms.
 no-asm = []
 
-# Workaround for codegen backends which haven't yet implemented `f16` and
-# `f128` support. Disabled any intrinsics which use those types.
-no-f16-f128 = []
-
 # Flag this library as the unstable compiler-builtins lib
 compiler-builtins = []
 

builtins-test/Cargo.toml

@@ -33,7 +33,6 @@ utest-macros = { git = "https://github.com/japaric/utest" }
 default = ["mangled-names"]
 c = ["compiler_builtins/c"]
 no-asm = ["compiler_builtins/no-asm"]
-no-f16-f128 = ["compiler_builtins/no-f16-f128"]
 mem = ["compiler_builtins/mem"]
 mangled-names = ["compiler_builtins/mangled-names"]
 # Skip tests that rely on f128 symbols being available on the system

ci/run.sh

@@ -36,8 +36,6 @@ else
     "${test_builtins[@]}" --features c --release
     "${test_builtins[@]}" --features no-asm
     "${test_builtins[@]}" --features no-asm --release
-    "${test_builtins[@]}" --features no-f16-f128
-    "${test_builtins[@]}" --features no-f16-f128 --release
     "${test_builtins[@]}" --benches
     "${test_builtins[@]}" --benches --release
 
@@ -63,8 +61,6 @@ symcheck+=(-- build-and-check)
 "${symcheck[@]}" "$target" -- -p compiler_builtins --features c --release
 "${symcheck[@]}" "$target" -- -p compiler_builtins --features no-asm
 "${symcheck[@]}" "$target" -- -p compiler_builtins --features no-asm --release
-"${symcheck[@]}" "$target" -- -p compiler_builtins --features no-f16-f128
-"${symcheck[@]}" "$target" -- -p compiler_builtins --features no-f16-f128 --release
 
 run_intrinsics_test() {
     build_args=(--verbose --manifest-path builtins-test-intrinsics/Cargo.toml)

compiler-builtins/Cargo.toml

@@ -45,10 +45,6 @@ c = ["dep:cc"]
 # the generic versions on all platforms.
 no-asm = []
 
-# Workaround for codegen backends which haven't yet implemented `f16` and
-# `f128` support. Disabled any intrinsics which use those types.
-no-f16-f128 = []
-
 # Flag this library as the unstable compiler-builtins lib
 compiler-builtins = []
 

compiler-builtins/configure.rs

@@ -95,16 +95,13 @@ pub fn configure_aliases(target: &Target) {
      * * https://github.com/rust-lang/rustc_codegen_cranelift/blob/c713ffab3c6e28ab4b4dd4e392330f786ea657ad/src/lib.rs#L196-L226
      */
 
-    // If the feature is set, disable both of these types.
-    let no_f16_f128 = target.cargo_features.iter().any(|s| s == "no-f16-f128");
-
     println!("cargo::rustc-check-cfg=cfg(f16_enabled)");
-    if target.reliable_f16 && !no_f16_f128 {
+    if target.reliable_f16 {
         println!("cargo::rustc-cfg=f16_enabled");
     }
 
     println!("cargo::rustc-check-cfg=cfg(f128_enabled)");
-    if target.reliable_f128 && !no_f16_f128 {
+    if target.reliable_f128 {
         println!("cargo::rustc-cfg=f128_enabled");
     }
 }

libm/configure.rs

@@ -143,16 +143,13 @@ fn emit_f16_f128_cfg(cfg: &Config) {
 
     /* See the compiler-builtins configure file for info about the meaning of these options */
 
-    // If the feature is set, disable both of these types.
-    let no_f16_f128 = cfg.cargo_features.iter().any(|s| s == "no-f16-f128");
-
     println!("cargo:rustc-check-cfg=cfg(f16_enabled)");
-    if cfg.reliable_f16 && !no_f16_f128 {
+    if cfg.reliable_f16 {
         println!("cargo:rustc-cfg=f16_enabled");
     }
 
     println!("cargo:rustc-check-cfg=cfg(f128_enabled)");
-    if cfg.reliable_f128 && !no_f16_f128 {
+    if cfg.reliable_f128 {
         println!("cargo:rustc-cfg=f128_enabled");
     }
 }