when open macro GENERATED_CODE_COVERAGE, fix compiler error and fd leak

src/arm/simulator-arm.cc

Index: src/arm/simulator-arm.cc
diff --git a/src/arm/simulator-arm.cc b/src/arm/simulator-arm.cc
index 60a5e806bee2fca1c0bd5d6b9192f2acc6299761..71b8277aa05bee4be95873d7cc657764bfe7322a 100644
--- a/src/arm/simulator-arm.cc
+++ b/src/arm/simulator-arm.cc
@@ -74,11 +74,17 @@ static FILE* coverage_log = NULL;
 
 static void InitializeCoverage() {
   char* file_name = getenv("V8_GENERATED_CODE_COVERAGE_LOG");
-  if (file_name != NULL) {
+  if (file_name != NULL && NULL == coverage_log) {
     coverage_log = fopen(file_name, "aw+");
   }
 }
 
+static void DeinitCoverageLog() {
+	if (coverage_log != NULL) {
+		fclose(coverage_log);
+		coverage_log = NULL;
+	}
+}
 
 void ArmDebugger::Stop(Instruction* instr) {
   // Get the stop code.
@@ -110,7 +116,8 @@ void ArmDebugger::Stop(Instruction* instr) {
 
 static void InitializeCoverage() {
 }
-
+static void DeinitCoverageLog() {
+}
 
 void ArmDebugger::Stop(Instruction* instr) {
   // Get the stop code.
@@ -775,6 +782,7 @@ Simulator::Simulator(Isolate* isolate) : isolate_(isolate) {
 
 
 Simulator::~Simulator() {
+	DeinitCoverageLog();
 }