[WebAssembly] Remove dependency of reference types from EH

[aheejin]

Summary

The new spec does not have exnref so EH does not have dependency of
the reference types proposal anymore.

clang/lib/Driver/ToolChains/WebAssembly.cpp

void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
 
   if (DriverArgs.getLastArg(options::OPT_fwasm_exceptions)) {
     // '-fwasm-exceptions' is not compatible with '-mno-exception-handling'
     if (DriverArgs.hasFlag(options::OPT_mno_exception_handing,
                            options::OPT_mexception_handing, false))
       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
           << "-fwasm-exceptions"
           << "-mno-exception-handling";
-    // '-fwasm-exceptions' is not compatible with '-mno-reference-types'
-    if (DriverArgs.hasFlag(options::OPT_mno_reference_types,
-                           options::OPT_mexception_handing, false))
-      getDriver().Diag(diag::err_drv_argument_not_allowed_with)
-          << "-fwasm-exceptions"
-          << "-mno-reference-types";
     // '-fwasm-exceptions' is not compatible with
     // '-mllvm -enable-emscripten-cxx-exceptions'
     for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
       if (StringRef(A->getValue(0)) == "-enable-emscripten-cxx-exceptions")
         getDriver().Diag(diag::err_drv_argument_not_allowed_with)
             << "-fwasm-exceptions"
             << "-mllvm -enable-emscripten-cxx-exceptions";
     }
-    // '-fwasm-exceptions' implies exception-handling and reference-types
+    // '-fwasm-exceptions' implies exception-handling feature
     CC1Args.push_back("-target-feature");
     CC1Args.push_back("+exception-handling");
-    CC1Args.push_back("-target-feature");
-    CC1Args.push_back("+reference-types");
   }
 }
 
 ToolChain::RuntimeLibType WebAssembly::GetDefaultRuntimeLibType() const {
   return ToolChain::RLT_CompilerRT;
 }
 
 ToolChain::CXXStdlibType

clang/test/Driver/wasm-toolchain.c

 // PTHREAD_NO_MUT_GLOBALS: invalid argument '-pthread' not allowed with '-mno-mutable-globals'
 
 // '-pthread' not allowed with '-mno-sign-ext'
 // RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
 // RUN:     --sysroot=/foo %s -pthread -mno-sign-ext 2>&1 \
 // RUN:   | FileCheck -check-prefix=PTHREAD_NO_SIGN_EXT %s
 // PTHREAD_NO_SIGN_EXT: invalid argument '-pthread' not allowed with '-mno-sign-ext'
 
-// '-fwasm-exceptions' sets +exception-handling and +reference-types
+// '-fwasm-exceptions' sets +exception-handling
 // RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
 // RUN:    --sysroot=/foo %s -fwasm-exceptions 2>&1 \
 // RUN:  | FileCheck -check-prefix=WASM_EXCEPTIONS %s
-// WASM_EXCEPTIONS: clang{{.*}}" "-cc1" {{.*}} "-target-feature" "+exception-handling" "-target-feature" "+reference-types"
+// WASM_EXCEPTIONS: clang{{.*}}" "-cc1" {{.*}} "-target-feature" "+exception-handling"
 
 // '-fwasm-exceptions' not allowed with '-mno-exception-handling'
 // RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
 // RUN:     --sysroot=/foo %s -fwasm-exceptions -mno-exception-handling 2>&1 \
 // RUN:   | FileCheck -check-prefix=WASM_EXCEPTIONS_NO_EH %s
 // WASM_EXCEPTIONS_NO_EH: invalid argument '-fwasm-exceptions' not allowed with '-mno-exception-handling'
 
-// '-fwasm-exceptions' not allowed with '-mno-reference-types'
-// RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
-// RUN:     --sysroot=/foo %s -fwasm-exceptions -mno-reference-types 2>&1 \
-// RUN:   | FileCheck -check-prefix=WASM_EXCEPTIONS_NO_REFTYPES %s
-// WASM_EXCEPTIONS_NO_REFTYPES: invalid argument '-fwasm-exceptions' not allowed with '-mno-reference-types'
-
 // '-fwasm-exceptions' not allowed with
 // '-mllvm -enable-emscripten-cxx-exceptions'
 // RUN: %clang -### -no-canonical-prefixes -target wasm32-unknown-unknown \
 // RUN:     --sysroot=/foo %s -fwasm-exceptions -mllvm -enable-emscripten-cxx-exceptions 2>&1 \
 // RUN:   | FileCheck -check-prefix=WASM_EXCEPTIONS_EMSCRIPTEN_EH %s
 // WASM_EXCEPTIONS_EMSCRIPTEN_EH: invalid argument '-fwasm-exceptions' not allowed with '-mllvm -enable-emscripten-cxx-exceptions'
 
 // RUN: %clang %s -### -fsanitize=address -target wasm32-unknown-emscripten 2>&1 | FileCheck -check-prefix=CHECK-ASAN-EMSCRIPTEN %s