fix what I broke with the double diff

I committed the wrong version.

hphp/runtime/base/string_data.cpp

@@ -824,7 +824,7 @@ int64_t StringData::toInt64(int base /* = 10 */) const {
 
 double StringData::toDouble() const {
   StringSlice s = slice();
-  if (s.len) return folly::to<double>(s.ptr);
+  if (s.len) return strtod(s.ptr, nullptr);
   return 0;
 }
 

hphp/runtime/base/zend/zend_collator.cpp

@@ -98,7 +98,7 @@ static double collator_u_strtod(const UChar *nptr, UChar **endptr) {
     }
 
     *bufpos = '\0';
-    value = folly::to<double>(numbuf);
+    value = strtod(numbuf, nullptr);
 
     if (numbuf != buf) {
       free(numbuf);

hphp/runtime/base/zend/zend_functions.cpp

@@ -17,7 +17,6 @@
 
 #include "hphp/runtime/base/zend/zend_functions.h"
 #include "hphp/runtime/base/zend/zend_strtod.h"
-#include "folly/Conv.h"
 
 namespace HPHP {
 
@@ -184,7 +183,7 @@ DataType is_numeric_string(const char *str, int length, int64_t *lval,
       int cmp = strcmp(&ptr[-digits], long_min_digits);
       if (!(cmp < 0 || (cmp == 0 && *str == '-'))) {
         if (dval) {
-          *dval = folly::to<double>(str);
+          *dval = strtod(str, nullptr);
         }
         return KindOfDouble;
       }

hphp/runtime/base/zend/zend_math.h

@@ -19,7 +19,6 @@
 #define incl_HPHP_ZEND_MATH_H_
 
 #include "hphp/util/base.h"
-#include "folly/Conv.h"
 
 namespace HPHP {
 ///////////////////////////////////////////////////////////////////////////////
@@ -116,7 +115,7 @@ inline double php_math_round(double value, int places,
     char buf[40];
     snprintf(buf, 39, "%15fe%d", tmp_value, -places);
     buf[39] = '\0';
-    tmp_value = folly::to<double>(buf);
+    tmp_value = strtod(buf, nullptr);
 
     /* couldn't convert to string and back */
     if (std::isinf(tmp_value)) {

hphp/runtime/base/zend/zend_scanf.cpp

@@ -1045,7 +1045,7 @@ int string_sscanf(const char *string, const char *format, int numVars,
       if (!(flags & SCAN_SUPPRESS)) {
         double dvalue;
         *end = '\0';
-        dvalue = folly::to<double>(buf);
+        dvalue = strtod(buf, nullptr);
         return_value.append(dvalue);
       }
       break;