GN/Win: quieter builds

It's hard to read the logs as they are now.  This simplifies down the descriptions, and stifles a warning about linking object files with no symbols into a static library.

CQ_INCLUDE_TRYBOTS=master.client.skia.compile:Build-Win-MSVC-x86-Debug-Exceptions-Trybot,Build-Win-MSVC-x86_64-Debug-GN-Trybot,Build-Win-MSVC-x86_64-Release-GN-Trybot
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3322

Change-Id: I52beb3b8405ebb2c370cad432669834b64baa840
Reviewed-on: https://skia-review.googlesource.com/3322
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
diff --git a/gn/BUILD.gn b/gn/BUILD.gn
index b4eb327..dfab7e2 100644
--- a/gn/BUILD.gn
+++ b/gn/BUILD.gn
@@ -364,6 +364,7 @@
       "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.obj",
     ]
     rspfile_content = "{{defines}} {{include_dirs}} {{cflags}} {{cflags_c}}"
+    description = "compile {{source}}"
   }
 
   tool("cxx") {
@@ -378,13 +379,13 @@
       "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.obj",
     ]
     rspfile_content = "{{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}}"
+    description = "compile {{source}}"
   }
 
   tool("alink") {
     rspfile = "{{output}}.rsp"
 
-    command =
-        "$env_setup$bin/lib.exe /nologo {{arflags}} /OUT:{{output}} @$rspfile"
+    command = "$env_setup$bin/lib.exe /nologo /ignore:4221 {{arflags}} /OUT:{{output}} @$rspfile"
     outputs = [
       # Ignore {{output_extension}} and always use .lib, there's no reason to
       # allow targets to override this extension on Windows.
@@ -395,6 +396,7 @@
 
     # inputs_newline works around a fixed per-line buffer size in the linker.
     rspfile_content = "{{inputs_newline}}"
+    description = "link {{output}}"
   }
 
   tool("link") {
@@ -413,10 +415,12 @@
 
     # inputs_newline works around a fixed per-line buffer size in the linker.
     rspfile_content = "{{inputs_newline}} {{libs}} {{solibs}} {{ldflags}}"
+    description = "link {{output}}"
   }
 
   tool("stamp") {
     command = "cmd.exe /c echo > {{output}}"
+    description = "stamp {{output}}"
   }
 }