Add addBuildOpt helper function for building option string

addBuildOpt should be called with the build option which is NOT
surrounded by spaces since it will add spaces to separate options
itself, if necessary.

Author: gicmo

src/library/blas/generic/common.c

@@ -22,6 +22,7 @@
 #include <clkern.h>
 #include <cltypes.h>
 #include <stdio.h>
+#include <ctype.h>
 
 #include "clblas-internal.h"
 
@@ -537,6 +538,22 @@ setupBuildOpts(
     }
 }
 
+void addBuildOpt(
+    char * opts,
+    size_t len,
+    const char * option)
+{
+    size_t l = strlen(opts);
+
+    if (l > 0 && !isspace(opts[l-1]) && l+1 < len) {
+      opts[l] = ' ';
+      opts[l+1]   = '\0';
+    }
+
+    strlcat(opts, option, len);
+}
+
+
 char VISIBILITY_HIDDEN
 *sprintfGranulation(char *buf, const SubproblemDim *dim, int level)
 {

src/library/blas/include/clblas-internal.h

@@ -240,6 +240,11 @@ setupBuildOpts(
     cl_device_id devID,
     MemoryPattern *mempat);
 
+void addBuildOpt(
+    char * opts,
+    size_t len,
+    const char * option);
+
 // Internal scatter image API
 
 int