add creal/cimag macros in complex.h (and use them in the functions defs)

src/complex/cimag.c

@@ -2,6 +2,5 @@
 
 double (cimag)(double complex z)
 {
-	union dcomplex u = {z};
-	return u.a[1];
+	return cimag(z);
 }

src/complex/cimagf.c

@@ -2,6 +2,5 @@
 
 float (cimagf)(float complex z)
 {
-	union fcomplex u = {z};
-	return u.a[1];
+	return cimagf(z);
 }

src/complex/cimagl.c

@@ -2,6 +2,5 @@
 
 long double (cimagl)(long double complex z)
 {
-	union lcomplex u = {z};
-	return u.a[1];
+	return cimagl(z);
 }

src/complex/creal.c

@@ -1,6 +1,6 @@
 #include <complex.h>
 
-double creal(double complex z)
+double (creal)(double complex z)
 {
-	return z;
+	return creal(z);
 }

src/complex/crealf.c

@@ -1,6 +1,6 @@
 #include <complex.h>
 
-float crealf(float complex z)
+float (crealf)(float complex z)
 {
-	return z;
+	return crealf(z);
 }

src/complex/creall.c

@@ -1,6 +1,6 @@
 #include <complex.h>
 
-long double creall(long double complex z)
+long double (creall)(long double complex z)
 {
-	return z;
+	return creall(z);
 }

src/internal/libm.h

@@ -173,14 +173,6 @@ union lcomplex {
 	long double a[2];
 };
 
-// FIXME: move to complex.h ?
-#define creal(z) ((double)(z))
-#define crealf(z) ((float)(z))
-#define creall(z) ((long double)(z))
-#define cimag(z) ((union dcomplex){(z)}.a[1])
-#define cimagf(z) ((union fcomplex){(z)}.a[1])
-#define cimagl(z) ((union lcomplex){(z)}.a[1])
-
 /* x + y*I is not supported properly by gcc */
 #define cpack(x,y) ((union dcomplex){.a={(x),(y)}}.z)
 #define cpackf(x,y) ((union fcomplex){.a={(x),(y)}}.z)