Contribution of PowerPC port.

build/toolchain.gypi

Index: build/toolchain.gypi
diff --git a/build/toolchain.gypi b/build/toolchain.gypi
index 45c1f9dac8e5658a205c1a977fff318363062ae5..958f4f8a8ce42c1fdbe76091a7679c44f1aa6d74 100644
--- a/build/toolchain.gypi
+++ b/build/toolchain.gypi
@@ -100,7 +100,9 @@
     'android_webview_build%': '<(android_webview_build)',
   },
   'conditions': [
-    ['host_arch=="ia32" or host_arch=="x64" or clang==1', {
+    ['host_arch=="ia32" or host_arch=="x64" or \
+      host_arch=="ppc" or host_arch=="ppc64" or \
+      clang==1', {
       'variables': {
         'host_cxx_is_biarch%': 1,
        },
@@ -110,6 +112,7 @@
       },
     }],
     ['target_arch=="ia32" or target_arch=="x64" or target_arch=="x87" or \
+      target_arch=="ppc" or target_arch=="ppc64" or \
       clang==1', {
       'variables': {
         'target_cxx_is_biarch%': 1,
@@ -250,6 +253,28 @@
           'V8_TARGET_ARCH_ARM64',
         ],
       }],
+      ['v8_target_arch=="ppc" or v8_target_arch=="ppc64"', {
+        'defines': [
+          'V8_TARGET_ARCH_PPC',
+        ],
+        'conditions': [
+          ['v8_target_arch=="ppc64"', {
+            'defines': [
+              'V8_TARGET_ARCH_PPC64',
+            ],
+          }],
+          ['v8_host_byteorder=="little"', {
+            'defines': [
+              'V8_TARGET_ARCH_PPC_LE',
+            ],
+          }],
+          ['v8_host_byteorder=="big"', {
+            'defines': [
+              'V8_TARGET_ARCH_PPC_BE',
+            ],
+          }],
+        ],
+      }],  # ppc
       ['v8_target_arch=="ia32"', {
         'defines': [
           'V8_TARGET_ARCH_IA32',
@@ -590,7 +615,7 @@
          or OS=="netbsd" or OS=="mac" or OS=="android" or OS=="qnx") and \
         (v8_target_arch=="arm" or v8_target_arch=="ia32" or \
          v8_target_arch=="x87" or v8_target_arch=="mips" or \
-         v8_target_arch=="mipsel")', {
+         v8_target_arch=="mipsel" or v8_target_arch=="ppc")', {
         'target_conditions': [
           ['_toolset=="host"', {
             'conditions': [
@@ -617,7 +642,8 @@
         ],
       }],
       ['(OS=="linux" or OS=="android") and \
-        (v8_target_arch=="x64" or v8_target_arch=="arm64")', {
+        (v8_target_arch=="x64" or v8_target_arch=="arm64" or \
+         v8_target_arch=="ppc64")', {
         'target_conditions': [
           ['_toolset=="host"', {
             'conditions': [