build: shrink bloated addon binaries on windows

PR-URL: #2060
Reviewed-By: Bartosz Sosnowski <[email protected]>

Author: codebytere

addon.gypi

@@ -1,7 +1,8 @@
 {
   'variables' : {
     'node_engine_include_dir%': 'deps/v8/include',
-    'node_host_binary%': 'node'
+    'node_host_binary%': 'node',
+    'node_with_ltcg%': 'true',
   },
   'target_defaults': {
     'type': 'loadable_module',
@@ -126,6 +127,26 @@
             'library_dirs': [ '<(node_root_dir)/$(ConfigurationName)' ],
             'libraries': [ '<@(node_engine_libs)' ],
           }],
+          ['node_with_ltcg=="true"', {
+            'msvs_settings': {
+              'VCCLCompilerTool': {
+                'WholeProgramOptimization': 'true' # /GL, whole program optimization, needed for LTCG
+              },
+              'VCLibrarianTool': {
+                'AdditionalOptions': [
+                  '/LTCG:INCREMENTAL', # incremental link-time code generation
+                ]
+              },
+              'VCLinkerTool': {
+                'OptimizeReferences': 2, # /OPT:REF
+                'EnableCOMDATFolding': 2, # /OPT:ICF
+                'LinkIncremental': 1, # disable incremental linking
+                'AdditionalOptions': [
+                  '/LTCG:INCREMENTAL', # incremental link-time code generation
+                ]
+              }
+            }
+          }]
         ],
         'libraries': [
           '-lkernel32.lib',