Fix scaler engine performance regression on Windows: compiling with /fp:fast option

Fix Windows: Image `_scaler` engine performance regression  #23

(cherry picked from commit db88b70)
(cherry picked from commit ec6c8c4)

Author: PierreRaybaut

setup.py

@@ -50,7 +50,7 @@ def compile_cython_extensions():
 # -------------------------------------------------------------------------------------
 
 MACROS_CPP = [("NPY_NO_DEPRECATED_API", "NPY_1_7_API_VERSION")]
-CFLAGS_CPP = ["/EHsc"] if is_msvc() else ["-Wall"]
+CFLAGS_CPP = ["/EHsc", "/fp:fast"] if is_msvc() else ["-Wall"]
 if platform.system() == "Darwin":
     CFLAGS_CPP += ["-std=c++11"]
 

src/pcolor.cpp

@@ -9,7 +9,6 @@
 #include <numpy/arrayobject.h>
 #ifdef _MSC_VER
 #include <float.h>
-#pragma fenv_access(on)
 #else
 #include <fenv.h>
 #endif

src/scaler.cpp

@@ -9,7 +9,6 @@
 #include <numpy/arrayobject.h>
 #ifdef _MSC_VER
 #include <float.h>
-#pragma fenv_access(on)
 #define FE_TOWARDZERO _RC_CHOP
 #define fegetround() (_controlfp(0, 0) & _MCW_RC)
 int fesetround(int r)