Rollup merge of rust-lang#73346 - aszenz:patch-1, r=cuviper

Add rust specific features to print target features

Fixes rust-lang#71583

`crt-static` is a rust specific target feature that's absent from llvm feature table, adding it there so that it shows under `rustc --print target-features`.

Probably the most native implementation I could think of, would love to get feedback.

src/rustllvm/PassWrapper.cpp

@@ -424,6 +424,12 @@ extern "C" void LLVMRustPrintTargetFeatures(LLVMTargetMachineRef TM) {
   printf("Available features for this target:\n");
   for (auto &Feature : FeatTable)
     printf("    %-*s - %s.\n", MaxFeatLen, Feature.Key, Feature.Desc);
+  printf("\nRust-specific features:\n");
+  printf("    %-*s - %s.\n",
+    MaxFeatLen,
+    "crt-static",
+    "Enables libraries with C Run-time Libraries(CRT) to be statically linked"
+  );
   printf("\n");
 
   printf("Use +feature to enable a feature, or -feature to disable it.\n"