[arm][arm64] Remove COHERENT_CACHE support

src/arm64/assembler-arm64.cc

Index: src/arm64/assembler-arm64.cc
diff --git a/src/arm64/assembler-arm64.cc b/src/arm64/assembler-arm64.cc
index 55256401a54615851d07fb6411241c855e0672d1..91563a4227afd0a54591a8eb4289a402acacb40c 100644
--- a/src/arm64/assembler-arm64.cc
+++ b/src/arm64/assembler-arm64.cc
@@ -51,26 +51,13 @@ void CpuFeatures::ProbeImpl(bool cross_compile) {
   // Only use statically determined features for cross compile (snapshot).
   if (cross_compile) return;
 
-  // Probe for runtime features
-  base::CPU cpu;
-  if (cpu.implementer() == base::CPU::NVIDIA &&
-      cpu.variant() == base::CPU::NVIDIA_DENVER &&
-      cpu.part() <= base::CPU::NVIDIA_DENVER_V10) {
-    // TODO(jkummerow): This is turned off as an experiment to see if it
-    // affects crash rates. Keep an eye on crash reports and either remove
-    // coherent cache support permanently, or re-enable it!
-    // supported_ |= 1u << COHERENT_CACHE;
-  }
+  // We used to probe for coherent cache support, but on older CPUs it
+  // causes crashes (crbug.com/524337), and newer CPUs don't even have
+  // the feature any more.
 }
 
-
 void CpuFeatures::PrintTarget() { }
-
-
-void CpuFeatures::PrintFeatures() {
-  printf("COHERENT_CACHE=%d\n", CpuFeatures::IsSupported(COHERENT_CACHE));
-}
-
+void CpuFeatures::PrintFeatures() {}
 
 // -----------------------------------------------------------------------------
 // CPURegList utilities.