[clang] add llvm abi support

Author: RossComputerGuy

clang/lib/Driver/Driver.cpp

@@ -1531,7 +1531,7 @@ Compilation *Driver::BuildCompilation(ArrayRef<const char *> ArgList) {
 
   // Check if the environment version is valid except wasm case.
   llvm::Triple Triple = TC.getTriple();
-  if (!Triple.isWasm()) {
+  if (!Triple.isWasm() && Triple.getEnvironment() != llvm::Triple::LLVM) {
     StringRef TripleVersionName = Triple.getEnvironmentVersionString();
     StringRef TripleObjectFormat =
         Triple.getObjectFormatTypeName(Triple.getObjectFormat());

clang/lib/Driver/ToolChains/Gnu.cpp

@@ -464,7 +464,7 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
       if (!Args.hasArg(options::OPT_shared)) {
         if (Args.hasArg(options::OPT_pg))
           crt1 = "gcrt1.o";
-        else if (IsPIE)
+        else if (IsPIE && Triple.getEnvironment() != llvm::Triple::LLVM)
           crt1 = "Scrt1.o";
         else if (IsStaticPIE)
           crt1 = "rcrt1.o";