Fix symbol list for mangled Mesa on Darwin.

When building mangled Mesa on Darwin, the exported symbols are
named `_mgluWhatever' instead of simply `_gluWhatever'.  When
using a list of exported symbols via the system ld's
`-exported_symbols_list' command line option (as done by mklib),
this resulted in error messages about exporting symbols which do
not exist.

Fortunately the file format accepts simple wildcards.  This throws
a wildcard so that the symbol list will match both the mangled and
non-mangled names, preventing the warning and actually exporting
the correct symbols in one shot.

src/glu/sgi/glu.exports.darwin

@@ -1,59 +1,59 @@
-_gluBeginCurve
-_gluBeginPolygon
-_gluBeginSurface
-_gluBeginTrim
-_gluBuild1DMipmapLevels
-_gluBuild1DMipmaps
-_gluBuild2DMipmapLevels
-_gluBuild2DMipmaps
-_gluBuild3DMipmapLevels
-_gluBuild3DMipmaps
-_gluCheckExtension
-_gluCylinder
-_gluDeleteNurbsRenderer
-_gluDeleteQuadric
-_gluDeleteTess
-_gluDisk
-_gluEndCurve
-_gluEndPolygon
-_gluEndSurface
-_gluEndTrim
-_gluErrorString
-_gluGetNurbsProperty
-_gluGetString
-_gluGetTessProperty
-_gluLoadSamplingMatrices
-_gluLookAt
-_gluNewNurbsRenderer
-_gluNewQuadric
-_gluNewTess
-_gluNextContour
-_gluNurbsCallback
-_gluNurbsCallbackData
-_gluNurbsCallbackDataEXT
-_gluNurbsCurve
-_gluNurbsProperty
-_gluNurbsSurface
-_gluOrtho2D
-_gluPartialDisk
-_gluPerspective
-_gluPickMatrix
-_gluProject
-_gluPwlCurve
-_gluQuadricCallback
-_gluQuadricDrawStyle
-_gluQuadricNormals
-_gluQuadricOrientation
-_gluQuadricTexture
-_gluScaleImage
-_gluSphere
-_gluTessBeginContour
-_gluTessBeginPolygon
-_gluTessCallback
-_gluTessEndContour
-_gluTessEndPolygon
-_gluTessNormal
-_gluTessProperty
-_gluTessVertex
-_gluUnProject
-_gluUnProject4
+_*gluBeginCurve
+_*gluBeginPolygon
+_*gluBeginSurface
+_*gluBeginTrim
+_*gluBuild1DMipmapLevels
+_*gluBuild1DMipmaps
+_*gluBuild2DMipmapLevels
+_*gluBuild2DMipmaps
+_*gluBuild3DMipmapLevels
+_*gluBuild3DMipmaps
+_*gluCheckExtension
+_*gluCylinder
+_*gluDeleteNurbsRenderer
+_*gluDeleteQuadric
+_*gluDeleteTess
+_*gluDisk
+_*gluEndCurve
+_*gluEndPolygon
+_*gluEndSurface
+_*gluEndTrim
+_*gluErrorString
+_*gluGetNurbsProperty
+_*gluGetString
+_*gluGetTessProperty
+_*gluLoadSamplingMatrices
+_*gluLookAt
+_*gluNewNurbsRenderer
+_*gluNewQuadric
+_*gluNewTess
+_*gluNextContour
+_*gluNurbsCallback
+_*gluNurbsCallbackData
+_*gluNurbsCallbackDataEXT
+_*gluNurbsCurve
+_*gluNurbsProperty
+_*gluNurbsSurface
+_*gluOrtho2D
+_*gluPartialDisk
+_*gluPerspective
+_*gluPickMatrix
+_*gluProject
+_*gluPwlCurve
+_*gluQuadricCallback
+_*gluQuadricDrawStyle
+_*gluQuadricNormals
+_*gluQuadricOrientation
+_*gluQuadricTexture
+_*gluScaleImage
+_*gluSphere
+_*gluTessBeginContour
+_*gluTessBeginPolygon
+_*gluTessCallback
+_*gluTessEndContour
+_*gluTessEndPolygon
+_*gluTessNormal
+_*gluTessProperty
+_*gluTessVertex
+_*gluUnProject
+_*gluUnProject4