win: Assert goma is not used with cl.exe, and stop setting symbol_level to 1 in non-clang goma builds.

We're removing support for MSVC on goma, so this combination of toggles
will be impossible soon. Assert it's unused, and remove a bit of code
I found that checked for this combination.

Bug: 1006238
Change-Id: Id00f887d37139262970d9d6a1a9c78fc18bb0bb5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1846674
Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#704463}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 1f02214abce0065e78718378e03dcb6064d58012

config/compiler/compiler.gni

@@ -222,15 +222,6 @@ if (symbol_level == -1) {
     # Reduce symbol level when it will cause invalid elf files to be created
     # (due to file size). https://crbug.com/648948.
     symbol_level = 1
-  } else if (is_win && use_goma && !is_clang) {
-    # goma doesn't support PDB files, so we disable symbols during goma
-    # compilation because otherwise the redundant debug information generated
-    # by visual studio (repeated in every .obj file) makes linker
-    # memory consumption and link times unsustainable (crbug.com/630074).
-    # Clang on windows does not have this issue.
-    # If you use is_win_fastlink = true or lld or clang then you can set
-    # symbol_level = 2 when using goma.
-    symbol_level = 1
   } else if (is_cros_chrome_sdk) {
     # Use lower symbol level in Simple Chrome build for faster link time.
     # For Simple Chrome, this should take precedence over is_official_build,

toolchain/goma.gni

@@ -27,3 +27,6 @@ declare_args() {
     }
   }
 }
+
+assert(!is_win || !use_goma || is_clang,
+       "cl.exe does not work on goma, use clang")