Detect cache line size on Linux for PPC hosts.

src/ppc/assembler-ppc.cc

Index: src/ppc/assembler-ppc.cc
diff --git a/src/ppc/assembler-ppc.cc b/src/ppc/assembler-ppc.cc
index d920eaa9a0782cc0c19ab2933ac2b50ab3cc7ed7..aed149bcab43403517c2d8a3f6b87124b194f13e 100644
--- a/src/ppc/assembler-ppc.cc
+++ b/src/ppc/assembler-ppc.cc
@@ -55,7 +55,7 @@ static unsigned CpuFeaturesImpliedByCompiler() {
 
 void CpuFeatures::ProbeImpl(bool cross_compile) {
   supported_ |= CpuFeaturesImpliedByCompiler();
-  cache_line_size_ = 128;
+  icache_line_size_ = 128;
 
   // Only use statically determined features for cross compile (snapshot).
   if (cross_compile) return;
@@ -85,6 +85,9 @@ void CpuFeatures::ProbeImpl(bool cross_compile) {
     // Assume support
     supported_ |= (1u << FPU);
   }
+  if (cpu.icache_line_size() != base::CPU::UNKNOWN_CACHE_LINE_SIZE) {
+    icache_line_size_ = cpu.icache_line_size();
+  }
 #elif V8_OS_AIX
   // Assume support FP support and default cache line size
   supported_ |= (1u << FPU);