started using cc crate

src/test/run-make/x86_64-fortanix-unknown-sgx-lvi/cc_plus_one_c.checks

@@ -0,0 +1,6 @@
+CHECK: cc_plus_one_c
+CHECK:      lfence
+CHECK:      popq
+CHECK-NEXT: popq [[REGISTER:%[a-z]+]]
+CHECK-NEXT: lfence
+CHECK-NEXT: jmpq *[[REGISTER]]

src/test/run-make/x86_64-fortanix-unknown-sgx-lvi/enclave/Cargo.toml

@@ -7,3 +7,6 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+
+[build-dependencies]
+cc = "1.0"

src/test/run-make/x86_64-fortanix-unknown-sgx-lvi/enclave/build.rs

@@ -0,0 +1,5 @@
+fn main() {
+    cc::Build::new()
+        .file("foo.c")
+        .compile("foo");
+}

src/test/run-make/x86_64-fortanix-unknown-sgx-lvi/enclave/foo.c

@@ -0,0 +1,4 @@
+
+int cc_plus_one_c(int *arg) {
+    return *arg + 1;
+}

src/test/run-make/x86_64-fortanix-unknown-sgx-lvi/enclave/src/main.rs

@@ -1,3 +1,11 @@
-fn main() {
-    println!("Hello, world!");
+extern {
+    fn cc_plus_one_c(arg : &u32) -> u32;
+}
+
+fn main() {
+    let value : u32 = 41;
+    
+    unsafe{
+        println!("Answer to the Ultimate Question of Life, the Universe, and Everything: {}!", cc_plus_one_c(&value));
+    }
 }

src/test/run-make/x86_64-fortanix-unknown-sgx-lvi/script.sh

@@ -12,10 +12,8 @@ function build {
             # HACK(eddyb) sets `RUSTC_BOOTSTRAP=1` so Cargo can accept nightly features.
             # These come from the top-level Rust workspace, that this crate is not a
             # member of, but Cargo tries to load the workspace `Cargo.toml` anyway.
-            env RUSTC_BOOTSTRAP=1  \
+            env RUSTC_BOOTSTRAP=1
                 cargo -v run --target $TARGET
-            env RUSTC_BOOTSTRAP=1  \
-                cargo -v run --target $TARGET --release 
         popd
     popd
 }
@@ -40,3 +38,4 @@ build
 #check "libunwind::Registers_x86_64::jumpto()" jumpto.checks
 
 check "std::io::stdio::_print::h87f0c238421c45bc" print.checks
+check cc_plus_one_c cc_plus_one_c.checks