build: remove /MP from default additonal options

PR-URL: #22661
Reviewed-By: João Reis <reis@janeasystems.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Bartosz Sosnowski <bartosz@janeasystems.com>

Author: skelliam

common.gypi

@@ -148,9 +148,9 @@
             'MinimalRebuild': 'false',
             'OmitFramePointers': 'false',
             'BasicRuntimeChecks': 3, # /RTC1
+            'MultiProcessorCompilation': 'true',
             'AdditionalOptions': [
               '/bigobj', # prevent error C1128 in VS2015
-              '/MP', # compile across multiple CPUs
             ],
           },
           'VCLinkerTool': {
@@ -255,8 +255,8 @@
             'EnableFunctionLevelLinking': 'true',
             'EnableIntrinsicFunctions': 'true',
             'RuntimeTypeInfo': 'false',
+            'MultiProcessorCompilation': 'true',
             'AdditionalOptions': [
-              '/MP', # compile across multiple CPUs
             ],
           }
         }