move intrinsics test from src/bin to examples

with this change the libc crate is not required when calling `cargo build -p
compiler-builtins`

ci/run.sh

@@ -41,10 +41,10 @@ esac
 # Verify that we haven't drop any intrinsic/symbol
 case $1 in
     thumb*)
-        xargo build --features c --target $1 --bin intrinsics
+        xargo build --features c --target $1 --example intrinsics
         ;;
     *)
-        cargo build --no-default-features --features c --target $1 --bin intrinsics
+        cargo build --no-default-features --features c --target $1 --example intrinsics
         ;;
 esac
 
@@ -52,12 +52,12 @@ esac
 # TODO(#79) fix the undefined references problem for debug-assertions+lto
 case $1 in
     thumb*)
-        RUSTFLAGS="-C debug-assertions=no" xargo rustc --no-default-features --features c --target $1 --bin intrinsics -- -C lto -C link-arg=-nostartfiles
-        xargo rustc --no-default-features --features c --target $1 --bin intrinsics --release -- -C lto
+        RUSTFLAGS="-C debug-assertions=no" xargo rustc --no-default-features --features c --target $1 --example intrinsics -- -C lto -C link-arg=-nostartfiles
+        xargo rustc --no-default-features --features c --target $1 --example intrinsics --release -- -C lto
         ;;
     *)
-        RUSTFLAGS="-C debug-assertions=no" cargo rustc --no-default-features --features c --target $1 --bin intrinsics -- -C lto
-        cargo rustc --no-default-features --features c --target $1 --bin intrinsics --release -- -C lto
+        RUSTFLAGS="-C debug-assertions=no" cargo rustc --no-default-features --features c --target $1 --example intrinsics -- -C lto
+        cargo rustc --no-default-features --features c --target $1 --example intrinsics --release -- -C lto
         ;;
 esac