add -lm to IRIX CC linking

[SVN r8566]

libs/compiler.cfg

@@ -63,14 +63,14 @@ irix
 irixcc
 IRIX CC 7.1.3.3
 CC -c -LANG:std -I%include %source
-CC -o boosttmp.exe -LANG:std -I%include %source
+CC -o boosttmp.exe -LANG:std -I%include %source -lm
 SGI IRIX CC<br>7.3.1.1m
 
 irix
 irixcc-clib
 IRIX CC 7.1.3.3 with <cXXX> headers
 CC -c -LANG:std -I$HOME/include -I%include %source
-CC -o boosttmp.exe -LANG:std -I$HOME/include -I%include %source
+CC -o boosttmp.exe -LANG:std -I$HOME/include -I%include %source -lm
 SGI IRIX CC<br>7.3.1.1m<br>clib
 
 irix