[WebAssembly] Temporarily disable bulk-memory with -pthread

Summary:
To prevent the instability of bulk-memory in the wasm backend from
blocking separate pthread testing, temporarily remove the logic that
adds -mbulk-memory in the presence of -pthread. Since browsers will
ship bulk memory before or alongside threads, this change will be
reverted as soon as bulk memory has stabilized in the backend.

Reviewers: sbc100

Subscribers: dschuff, jgravelle-google, aheejin, sunfish, jfb, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58854

llvm-svn: 355248
diff --git a/clang/lib/Driver/ToolChains/WebAssembly.cpp b/clang/lib/Driver/ToolChains/WebAssembly.cpp
index ce28d44..0104cbb 100644
--- a/clang/lib/Driver/ToolChains/WebAssembly.cpp
+++ b/clang/lib/Driver/ToolChains/WebAssembly.cpp
@@ -124,8 +124,7 @@
                          options::OPT_fno_use_init_array, true))
     CC1Args.push_back("-fuse-init-array");
 
-  // '-pthread' implies '-target-feature +atomics' and
-  // '-target-feature +bulk-memory'
+  // '-pthread' implies '-target-feature +atomics'
   if (DriverArgs.hasFlag(options::OPT_pthread, options::OPT_no_pthread,
                          false)) {
     if (DriverArgs.hasFlag(options::OPT_mno_atomics, options::OPT_matomics,
@@ -133,27 +132,8 @@
       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
           << "-pthread"
           << "-mno-atomics";
-    if (DriverArgs.hasFlag(options::OPT_mno_bulk_memory,
-                           options::OPT_mbulk_memory, false))
-      getDriver().Diag(diag::err_drv_argument_not_allowed_with)
-          << "-pthread"
-          << "-mno-bulk-memory";
     CC1Args.push_back("-target-feature");
     CC1Args.push_back("+atomics");
-    CC1Args.push_back("-target-feature");
-    CC1Args.push_back("+bulk-memory");
-  }
-
-  // '-matomics' implies '-mbulk-memory'
-  if (DriverArgs.hasFlag(options::OPT_matomics, options::OPT_mno_atomics,
-                         false)) {
-    if (DriverArgs.hasFlag(options::OPT_mno_bulk_memory,
-                           options::OPT_mbulk_memory, false))
-      getDriver().Diag(diag::err_drv_argument_not_allowed_with)
-          << "-matomics"
-          << "-mno-bulk-memory";
-    CC1Args.push_back("-target-feature");
-    CC1Args.push_back("+bulk-memory");
   }
 }