Contribution of PowerPC port.

src/base/build_config.h

Index: src/base/build_config.h
diff --git a/src/base/build_config.h b/src/base/build_config.h
index c66d6a5cc4c6776e8ee1dfff369c35426b0d6309..e984face876917e20d0bbd5575075f8e88b2ceda 100644
--- a/src/base/build_config.h
+++ b/src/base/build_config.h
@@ -48,6 +48,13 @@
 #elif defined(__MIPSEB__) || defined(__MIPSEL__)
 #define V8_HOST_ARCH_MIPS 1
 #define V8_HOST_ARCH_32_BIT 1
+#elif defined(__PPC__) || defined(_ARCH_PPC)
+#define V8_HOST_ARCH_PPC 1
+#if defined(__PPC64__) || defined(_ARCH_PPC64)
+#define V8_HOST_ARCH_64_BIT 1
+#else
+#define V8_HOST_ARCH_32_BIT 1
+#endif
 #else
 #error "Host architecture was not detected as supported by v8"
 #endif
@@ -65,9 +72,9 @@
 // Target architecture detection. This may be set externally. If not, detect
 // in the same way as the host architecture, that is, target the native
 // environment as presented by the compiler.
-#if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_X87 && \
+#if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_X87 &&   \
     !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS && \
-    !V8_TARGET_ARCH_MIPS64
+    !V8_TARGET_ARCH_MIPS64 && !V8_TARGET_ARCH_PPC
 #if defined(_M_X64) || defined(__x86_64__)
 #define V8_TARGET_ARCH_X64 1
 #elif defined(_M_IX86) || defined(__i386__)
@@ -104,6 +111,12 @@
 #define V8_TARGET_ARCH_32_BIT 1
 #elif V8_TARGET_ARCH_MIPS64
 #define V8_TARGET_ARCH_64_BIT 1
+#elif V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC64
+#define V8_TARGET_ARCH_64_BIT 1
+#else
+#define V8_TARGET_ARCH_32_BIT 1
+#endif
 #elif V8_TARGET_ARCH_X87
 #define V8_TARGET_ARCH_32_BIT 1
 #else
@@ -154,6 +167,10 @@
 #define V8_TARGET_LITTLE_ENDIAN 1
 #elif V8_TARGET_ARCH_X87
 #define V8_TARGET_LITTLE_ENDIAN 1
+#elif V8_TARGET_ARCH_PPC_LE
+#define V8_TARGET_LITTLE_ENDIAN 1
+#elif V8_TARGET_ARCH_PPC_BE
+#define V8_TARGET_BIG_ENDIAN 1
 #else
 #error Unknown target architecture endianness
 #endif