Reland of enable compilation of compiler runtime for iOS simulator.

Was reverted in https://codereview.chromium.org/1893353002/ and the
underlying issue has since been fixed.

This is required to enable ASan and coverage on simulators (and
other tools like UBSan, TSan, ...).

BUG=450379,602649

Review-Url: https://codereview.chromium.org/2344573003
Cr-Commit-Position: refs/heads/master@{#418896}

tools/clang/scripts/package.py

@@ -211,11 +211,12 @@ def main():
                  'lib/libBlinkGCPlugin.' + so_ext,
                  ])
   if sys.platform == 'darwin':
-    want.extend([# Copy only the OSX (ASan and profile) and iossim (ASan)
-                 # runtime libraries:
+    want.extend([# Copy only the OSX and iossim (ASan and profile) runtime
+                 # libraries:
                  'lib/clang/*/lib/darwin/*asan_osx*',
                  'lib/clang/*/lib/darwin/*asan_iossim*',
                  'lib/clang/*/lib/darwin/*profile_osx*',
+                 'lib/clang/*/lib/darwin/*profile_iossim*',
                  ])
   elif sys.platform.startswith('linux'):
     # Copy the libstdc++.so.6 we linked Clang against so it can run.

tools/clang/scripts/update.py

@@ -686,6 +686,8 @@ def UpdateClang(args):
   compiler_rt_args = base_cmake_args + [
       '-DCMAKE_C_FLAGS=' + ' '.join(cflags),
       '-DCMAKE_CXX_FLAGS=' + ' '.join(cxxflags)]
+  if sys.platform == 'darwin':
+    compiler_rt_args += ['-DCOMPILER_RT_ENABLE_IOS=ON']
   if sys.platform != 'win32':
     compiler_rt_args += ['-DLLVM_CONFIG_PATH=' +
                          os.path.join(LLVM_BUILD_DIR, 'bin', 'llvm-config'),