[WebAssembly] Initial driver support for standard library paths.

llvm-svn: 261560
diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index 165d534..a0fad02 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -4468,6 +4468,11 @@
 WebAssembly::WebAssembly(const Driver &D, const llvm::Triple &Triple,
                          const llvm::opt::ArgList &Args)
   : ToolChain(D, Triple, Args) {
+
+  assert(Triple.isArch32Bit() != Triple.isArch64Bit());
+  getFilePaths().push_back(
+      getDriver().SysRoot + "/lib" + (Triple.isArch32Bit() ? "32" : "64"));
+
   // Use LLD by default.
   DefaultLinker = "lld";
 }