Detect cache line size on Linux for PPC hosts.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index e65209b0fe773c84620226e73040e0bcbedd31ac..24c01ffb1adec3849ed80887162780e939aed9a0 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -223,9 +223,14 @@ class CpuFeatures : public AllStatic {
 
   static inline bool SupportsCrankshaft();
 
-  static inline unsigned cache_line_size() {
-    DCHECK(cache_line_size_ != 0);
-    return cache_line_size_;
+  static inline unsigned icache_line_size() {
+    DCHECK(icache_line_size_ != 0);
+    return icache_line_size_;
+  }
+
+  static inline unsigned dcache_line_size() {
+    DCHECK(dcache_line_size_ != 0);
+    return dcache_line_size_;
   }
 
   static void PrintTarget();
@@ -241,7 +246,8 @@ class CpuFeatures : public AllStatic {
   static void ProbeImpl(bool cross_compile);
 
   static unsigned supported_;
-  static unsigned cache_line_size_;
+  static unsigned icache_line_size_;
+  static unsigned dcache_line_size_;
   static bool initialized_;
   DISALLOW_COPY_AND_ASSIGN(CpuFeatures);
 };