Update targets to use target_abi

All eabi targets have target_abi = "eabi".
All eabihf targets have target_abi = "eabihf".
armv6_unknown_freebsd and armv7_unknown_freebsd have target_abi = "eabihf".
All abi64 targets have target_abi = "abi64".
All ilp32 targets have target_abi = "ilp32".
All softfloat targets have target_abi = "softfloat".
All *-uwp-windows-* targets have target_abi = "uwp".
All spe targets have target_abi = "spe".
All macabi targets have target_abi = "macabi".
aarch64-apple-ios-sim has target_abi = "sim".
x86_64-fortanix-unknown-sgx has target_abi = "fortanix".
x86_64-unknown-linux-gnux32 has target_abi = "x32".

Add FIXME entries for targets for which existing values need to change
once cfg_target_abi becomes stable. (All of them are tier 3 targets.)

Add a test for target_abi in `--print cfg`.

Author: joshtriplett

compiler/rustc_target/src/spec/aarch64_be_unknown_linux_gnu_ilp32.rs

@@ -10,6 +10,11 @@ pub fn target() -> Target {
         pointer_width: 32,
         data_layout: "E-m:e-p:32:32-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".to_string(),
         arch: "aarch64".to_string(),
-        options: TargetOptions { mcount: "\u{1}_mcount".to_string(), endian: Endian::Big, ..base },
+        options: TargetOptions {
+            abi: "ilp32".to_string(),
+            mcount: "\u{1}_mcount".to_string(),
+            endian: Endian::Big,
+            ..base
+        },
     }
 }

compiler/rustc_target/src/spec/aarch64_unknown_linux_gnu_ilp32.rs

@@ -7,6 +7,7 @@ pub fn target() -> Target {
         data_layout: "e-m:e-p:32:32-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".to_string(),
         arch: "aarch64".to_string(),
         options: TargetOptions {
+            abi: "ilp32".to_string(),
             max_atomic_width: Some(128),
             mcount: "\u{1}_mcount".to_string(),
             ..super::linux_gnu_base::opts()

compiler/rustc_target/src/spec/aarch64_unknown_none_softfloat.rs

@@ -10,6 +10,7 @@ use super::{LinkerFlavor, LldFlavor, PanicStrategy, RelocModel, Target, TargetOp
 
 pub fn target() -> Target {
     let opts = TargetOptions {
+        abi: "softfloat".to_string(),
         linker_flavor: LinkerFlavor::Lld(LldFlavor::Ld),
         linker: Some("rust-lld".to_owned()),
         features: "+strict-align,-neon,-fp-armv8".to_string(),

compiler/rustc_target/src/spec/apple_sdk_base.rs

@@ -14,6 +14,15 @@ pub enum Arch {
     Arm64_sim,
 }
 
+fn target_abi(arch: Arch) -> String {
+    match arch {
+        Armv7 | Armv7s | Arm64 | I386 | X86_64 => "",
+        X86_64_macabi | Arm64_macabi => "macabi",
+        Arm64_sim => "sim",
+    }
+    .to_string()
+}
+
 fn target_cpu(arch: Arch) -> String {
     match arch {
         Armv7 => "cortex-a8", // iOS7 is supported on iPhone 4 and higher
@@ -39,6 +48,7 @@ fn link_env_remove(arch: Arch) -> Vec<String> {
 
 pub fn opts(os: &str, arch: Arch) -> TargetOptions {
     TargetOptions {
+        abi: target_abi(arch),
         cpu: target_cpu(arch),
         dynamic_linking: false,
         executables: true,

compiler/rustc_target/src/spec/arm_linux_androideabi.rs

@@ -7,6 +7,7 @@ pub fn target() -> Target {
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         arch: "arm".to_string(),
         options: TargetOptions {
+            abi: "eabi".to_string(),
             // https://developer.android.com/ndk/guides/abis.html#armeabi
             features: "+strict-align,+v5te".to_string(),
             max_atomic_width: Some(32),

compiler/rustc_target/src/spec/arm_unknown_linux_gnueabi.rs

@@ -7,6 +7,7 @@ pub fn target() -> Target {
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         arch: "arm".to_string(),
         options: TargetOptions {
+            abi: "eabi".to_string(),
             features: "+strict-align,+v6".to_string(),
             max_atomic_width: Some(64),
             mcount: "\u{1}__gnu_mcount_nc".to_string(),

compiler/rustc_target/src/spec/arm_unknown_linux_gnueabihf.rs

@@ -7,6 +7,7 @@ pub fn target() -> Target {
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         arch: "arm".to_string(),
         options: TargetOptions {
+            abi: "eabihf".to_string(),
             features: "+strict-align,+v6,+vfp2,-d32".to_string(),
             max_atomic_width: Some(64),
             mcount: "\u{1}__gnu_mcount_nc".to_string(),

compiler/rustc_target/src/spec/arm_unknown_linux_musleabi.rs

@@ -10,6 +10,7 @@ pub fn target() -> Target {
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         arch: "arm".to_string(),
         options: TargetOptions {
+            abi: "eabi".to_string(),
             // Most of these settings are copied from the arm_unknown_linux_gnueabi
             // target.
             features: "+strict-align,+v6".to_string(),

compiler/rustc_target/src/spec/arm_unknown_linux_musleabihf.rs

@@ -10,6 +10,7 @@ pub fn target() -> Target {
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         arch: "arm".to_string(),
         options: TargetOptions {
+            abi: "eabihf".to_string(),
             // Most of these settings are copied from the arm_unknown_linux_gnueabihf
             // target.
             features: "+strict-align,+v6,+vfp2,-d32".to_string(),

compiler/rustc_target/src/spec/armebv7r_none_eabi.rs

@@ -11,6 +11,7 @@ pub fn target() -> Target {
         data_layout: "E-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         arch: "arm".to_string(),
         options: TargetOptions {
+            abi: "eabi".to_string(),
             endian: Endian::Big,
             linker_flavor: LinkerFlavor::Lld(LldFlavor::Ld),
             executables: true,