Rollup merge of rust-lang#48466 - sanxiyn:no-neon, r=alexcrichton

Disable NEON on musl ARMv7

`armv7-unknown-linux-musleabihf` target diverged a bit from `armv7-unknown-linux-gnueabihf` target. This PR re-syncs them.

Fix rust-lang#47765.

src/librustc_back/target/armv7_unknown_linux_musleabihf.rs

@@ -12,13 +12,7 @@ use LinkerFlavor;
 use target::{Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
- let mut base = super::linux_musl_base::opts();
-
- // Most of these settings are copied from the armv7_unknown_linux_gnueabihf
- // target.
- base.features = "+v7,+vfp3,+neon".to_string();
- base.cpu = "cortex-a8".to_string();
- base.max_atomic_width = Some(64);
+ let base = super::linux_musl_base::opts();
  Ok(Target {
  // It's important we use "gnueabihf" and not "musleabihf" here. LLVM
  // uses it to determine the calling convention and float ABI, and LLVM
@@ -33,9 +27,15 @@ pub fn target() -> TargetResult {
  target_env: "musl".to_string(),
  target_vendor: "unknown".to_string(),
  linker_flavor: LinkerFlavor::Gcc,
+
+ // Most of these settings are copied from the armv7_unknown_linux_gnueabihf
+ // target.
  options: TargetOptions {
+ features: "+v7,+vfp3,+d16,+thumb2,-neon".to_string(),
+ cpu: "generic".to_string(),
+ max_atomic_width: Some(64),
  abi_blacklist: super::arm_base::abi_blacklist(),
  .. base
- },
+ }
  })
 }