clang build: enable in-process cc1 at clang build time instead of with a compiler flag.

Minor code cleanup; no behavior change.

Bug: 1049161
Change-Id: Ic5306bf949074a4bc102aac1e667e233a1604d27
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2095883Reviewed-by: Hans Wennborg <hans@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#749174}

build/config/compiler/BUILD.gn

@@ -499,12 +499,6 @@ config("compiler") {
       "-Xclang",
       "-instcombine-lower-dbg-declare=0",
     ]
-
-    if (!is_chromeos && default_toolchain != "//build/toolchain/cros:target") {
-      # TODO(https://crbug.com/1049161): Remove '-DCLANG_SPAWN_CC1=ON' from build.py instead
-      # once this change has marinated a bit.
-      cflags += [ "-fintegrated-cc1" ]
-    }
   }
 
   # C11/C++11 compiler flags setup.

tools/clang/scripts/build.py

@@ -475,8 +475,6 @@ def main():
       '-DCOMPILER_RT_USE_LIBCXX=NO',
       # Don't run Go bindings tests; PGO makes them confused.
       '-DLLVM_INCLUDE_GO_TESTS=OFF',
-      # TODO(b/148147812) Goma client doesn't handle in-process cc1.
-      '-DCLANG_SPAWN_CC1=ON',
   ]
 
   if args.gcc_toolchain:

tools/clang/scripts/update.py

@@ -41,7 +41,7 @@ import zipfile
 # Reverting problematic clang rolls is safe, though.
 CLANG_REVISION = '9284abd0040afecfd619dbcf1b244a8b533291c9'
 CLANG_SVN_REVISION = 'n344329'
-CLANG_SUB_REVISION = 2
+CLANG_SUB_REVISION = 4
 
 PACKAGE_VERSION = '%s-%s-%s' % (CLANG_SVN_REVISION, CLANG_REVISION[:8],
                                 CLANG_SUB_REVISION)