Updates the documentation of xGEMV and xGBMV related to when M=0 and N=0

Author: weslleyspereira

BLAS/SRC/cgbmv.f

@@ -148,6 +148,7 @@
 *>           ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
 *>           Before entry, the incremented array Y must contain the
 *>           vector y. On exit, Y is overwritten by the updated vector y.
+*>           If either m or n is zero, then Y not referenced.
 *> \endverbatim
 *>
 *> \param[in] INCY

BLAS/SRC/cgemv.f

@@ -119,6 +119,7 @@
 *>           Before entry with BETA non-zero, the incremented array Y
 *>           must contain the vector y. On exit, Y is overwritten by the
 *>           updated vector y.
+*>           If either m or n is zero, then Y not referenced.
 *> \endverbatim
 *>
 *> \param[in] INCY

BLAS/SRC/dgbmv.f

@@ -146,6 +146,7 @@
 *>           ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
 *>           Before entry, the incremented array Y must contain the
 *>           vector y. On exit, Y is overwritten by the updated vector y.
+*>           If either m or n is zero, then Y not referenced.
 *> \endverbatim
 *>
 *> \param[in] INCY

BLAS/SRC/dgemv.f

@@ -117,6 +117,7 @@
 *>           Before entry with BETA non-zero, the incremented array Y
 *>           must contain the vector y. On exit, Y is overwritten by the
 *>           updated vector y.
+*>           If either m or n is zero, then Y not referenced.
 *> \endverbatim
 *>
 *> \param[in] INCY

BLAS/SRC/sgbmv.f

@@ -146,6 +146,7 @@
 *>           ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
 *>           Before entry, the incremented array Y must contain the
 *>           vector y. On exit, Y is overwritten by the updated vector y.
+*>           If either m or n is zero, then Y not referenced.
 *> \endverbatim
 *>
 *> \param[in] INCY

BLAS/SRC/sgemv.f

@@ -117,6 +117,7 @@
 *>           Before entry with BETA non-zero, the incremented array Y
 *>           must contain the vector y. On exit, Y is overwritten by the
 *>           updated vector y.
+*>           If either m or n is zero, then Y not referenced.
 *> \endverbatim
 *>
 *> \param[in] INCY

BLAS/SRC/zgbmv.f

@@ -148,6 +148,7 @@
 *>           ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
 *>           Before entry, the incremented array Y must contain the
 *>           vector y. On exit, Y is overwritten by the updated vector y.
+*>           If either m or n is zero, then Y not referenced.
 *> \endverbatim
 *>
 *> \param[in] INCY

BLAS/SRC/zgemv.f

@@ -119,6 +119,7 @@
 *>           Before entry with BETA non-zero, the incremented array Y
 *>           must contain the vector y. On exit, Y is overwritten by the
 *>           updated vector y.
+*>           If either m or n is zero, then Y not referenced.
 *> \endverbatim
 *>
 *> \param[in] INCY