Remove no longer necessary targets dir

All target specs we use are now built into rustc.

mk/prefix.mk

@@ -241,7 +241,6 @@ else
 	export PATH="$(PREFIX_FREESTANDING_PATH):$$PATH" && \
 	export CARGO="env -u CARGO -u RUSTUP_TOOLCHAIN cargo" && \
 	export CC_$(subst -,_,$(TARGET))="$(GNU_TARGET)-gcc -isystem $(ROOT)/$@.partial/$(GNU_TARGET)/include" && \
-	export RUST_TARGET_PATH="$(ROOT)/targets" && \
 	$(MAKE) clean && \
 	$(MAKE) -j 1 all && \
 	$(MAKE) -j 1 install DESTDIR="$(ROOT)/$@.partial/$(GNU_TARGET)"

targets/README

@@ -1,3 +0,0 @@
-This contains a target definition for targets that Redox supports but have not
-yet been added to the upstream rust, specifically for compiling relibc in
-freestanding mode.

targets/i686-unknown-redox.json

@@ -1,49 +0,0 @@
-{
-  "arch": "x86",
-  "cpu": "pentiumpro",
-  "crt-objects-fallback": "false",
-  "crt-static-allows-dylibs": true,
-  "crt-static-default": true,
-  "crt-static-respected": true,
-  "data-layout": "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-i128:128-f64:32:64-f80:32-n8:16:32-S128",
-  "dynamic-linking": true,
-  "env": "relibc",
-  "has-rpath": true,
-  "has-thread-local": true,
-  "late-link-args": {
-    "gnu-cc": [
-      "-lgcc"
-    ],
-    "gnu-lld-cc": [
-      "-lgcc"
-    ]
-  },
-  "linker-flavor": "gnu-cc",
-  "llvm-target": "i686-unknown-redox",
-  "max-atomic-width": 64,
-  "metadata": {
-    "description": null,
-    "host_tools": null,
-    "std": null,
-    "tier": null
-  },
-  "os": "redox",
-  "plt-by-default": false,
-  "position-independent-executables": true,
-  "pre-link-args": {
-    "gnu-cc": [
-      "-m32"
-    ],
-    "gnu-lld-cc": [
-      "-m32"
-    ]
-  },
-  "relro-level": "full",
-  "stack-probes": {
-    "kind": "call"
-  },
-  "target-family": [
-    "unix"
-  ],
-  "target-pointer-width": 32
-}

targets/riscv64gc-unknown-redox.json

@@ -1,41 +0,0 @@
-{
-  "arch": "riscv64",
-  "code-model": "medium",
-  "cpu": "generic-rv64",
-  "crt-objects-fallback": "false",
-  "crt-static-allows-dylibs": true,
-  "crt-static-default": true,
-  "crt-static-respected": true,
-  "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
-  "dynamic-linking": true,
-  "env": "relibc",
-  "features": "+m,+a,+f,+d,+c",
-  "has-rpath": true,
-  "has-thread-local": true,
-  "late-link-args": {
-    "gnu-cc": [
-      "-lgcc"
-    ],
-    "gnu-lld-cc": [
-      "-lgcc"
-    ]
-  },
-  "linker-flavor": "gnu-cc",
-  "llvm-abiname": "lp64d",
-  "llvm-target": "riscv64-unknown-redox",
-  "max-atomic-width": 64,
-  "metadata": {
-    "description": null,
-    "host_tools": null,
-    "std": null,
-    "tier": null
-  },
-  "os": "redox",
-  "plt-by-default": false,
-  "position-independent-executables": true,
-  "relro-level": "full",
-  "target-family": [
-    "unix"
-  ],
-  "target-pointer-width": 64
-}