lapack/laed3: fix MinGW build for slaed3

common_interface.h declares slamc3 as returning FLOATRET when
NEED_F2CCONV is enabled, but laed3_single.c and laed3_parallel.c
redeclared LAMC3 as returning FLOAT. This causes conflicting-type
errors in MinGW builds.

Use FLOATRET for the local LAMC3 prototype so it matches the shared
declaration. Also undefine the Windows max macro before the local
max definition in laed3_parallel.c to avoid macro redefinition
warnings.

Author: nakatamaho

lapack/laed3/laed3_parallel.c

@@ -33,6 +33,9 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <stdio.h>
 #include "common.h"
 
+#ifdef max
+#undef max
+#endif
 #define max(a,b) ((a) > (b) ? (a) : (b))
 #define copysign(x,y) ((y) < 0 ? ((x) < 0 ? (x) : -(x)) : ((x) < 0 ? -(x) : (x)))
 
@@ -54,7 +57,7 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define LASET  BLASFUNC(slaset)
 #endif
 
-FLOAT LAMC3(FLOAT *, FLOAT *);
+FLOATRET LAMC3(FLOAT *, FLOAT *);
 void LAED4(blasint *, blasint *, FLOAT *, FLOAT *, FLOAT *, FLOAT *, FLOAT *, blasint *);
 void LACPY(char *, blasint *, blasint *, FLOAT *, blasint *, FLOAT *, blasint *);
 void LASET(char *, blasint *, blasint *, FLOAT *, FLOAT *, FLOAT *, blasint *);

lapack/laed3/laed3_single.c

@@ -53,7 +53,7 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define LASET  BLASFUNC(slaset)
 #endif
 
-FLOAT LAMC3(FLOAT *, FLOAT *);
+FLOATRET LAMC3(FLOAT *, FLOAT *);
 void LAED4(blasint *, blasint *, FLOAT *, FLOAT *, FLOAT *, FLOAT *, FLOAT *, blasint *);
 void LACPY(char *, blasint *, blasint *, FLOAT *, blasint *, FLOAT *, blasint *);
 void LASET(char *, blasint *, blasint *, FLOAT *, FLOAT *, FLOAT *, blasint *);