Tidy-up for Mac makefile build configs

config/Makefile.darwin

@@ -2,9 +2,9 @@ GLEW_DEST = /usr/local
 NAME = $(GLEW_NAME)
 CC = cc
 LD = cc
-CFLAGS.EXTRA = -dynamic -fno-common
+CFLAGS.EXTRA += -dynamic -fno-common
 CFLAGS.EXTRA += -std=c89 -pedantic
-#CFLAGS.EXTRA += -no-cpp-precomp
+CFLAGS.EXTRA += -fPIC
 LDFLAGS.EXTRA =
 ifneq (undefined, $(origin GLEW_APPLE_GLX))
 CFLAGS.EXTRA += -I/usr/X11R6/include -D'GLEW_APPLE_GLX'
@@ -16,7 +16,6 @@ LDFLAGS.STATIC =
 LDFLAGS.DYNAMIC =
 WARN = -Wall -W
 POPT = -Os
-CFLAGS.EXTRA += -fPIC
 BIN.SUFFIX =
 LIB.SONAME    = lib$(NAME).$(SO_MAJOR).dylib
 LIB.DEVLNK    = lib$(NAME).dylib

config/Makefile.darwin-gcc6

@@ -6,10 +6,10 @@ CC = gcc-6
 LD = gcc-6
 CFLAGS.EXTRA = -dynamic -fno-common
 CFLAGS.EXTRA += -std=c89
+CFLAGS.EXTRA += -fPIC
 # Lots of warnings with -pedantic
 # warning: ISO C forbids conversion of object pointer to function pointer type
 #CFLAGS.EXTRA += -pedantic
-#CFLAGS.EXTRA += -no-cpp-precomp
 LDFLAGS.EXTRA =
 ifneq (undefined, $(origin GLEW_APPLE_GLX))
 CFLAGS.EXTRA += -I/usr/X11R6/include -D'GLEW_APPLE_GLX'
@@ -21,7 +21,6 @@ LDFLAGS.STATIC =
 LDFLAGS.DYNAMIC =
 WARN = -Wall -W
 POPT = -Os
-CFLAGS.EXTRA += -fPIC
 BIN.SUFFIX =
 LIB.SONAME    = lib$(NAME).$(SO_MAJOR).dylib
 LIB.DEVLNK    = lib$(NAME).dylib

config/Makefile.darwin-ppc

-# Note: PPC is no longer actively maintained for GLEW, but this configuration
+# Note: Mac PPC is obsolete but the configuration
 #       is here for reference.
 GLEW_DEST = /usr/local
 NAME = $(GLEW_NAME)
 CC = cc
 LD = cc
-CFLAGS.EXTRA = -arch ppc -dynamic -fno-common
-#CFLAGS.EXTRA += -no-cpp-precomp
+CFLAGS.EXTRA += -arch ppc
+CFLAGS.EXTRA += -dynamic -fno-common
+CFLAGS.EXTRA += -std=c89 -pedantic
+CFLAGS.EXTRA += -fPIC
 LDFLAGS.EXTRA = -arch ppc
 ifneq (undefined, $(origin GLEW_APPLE_GLX))
 CFLAGS.EXTRA += -I/usr/X11R6/include -D'GLEW_APPLE_GLX'
@@ -17,7 +19,6 @@ LDFLAGS.STATIC =
 LDFLAGS.DYNAMIC =
 WARN = -Wall -W
 POPT = -Os
-CFLAGS.EXTRA += -fPIC
 BIN.SUFFIX =
 LIB.SONAME    = lib$(NAME).$(SO_MAJOR).dylib
 LIB.DEVLNK    = lib$(NAME).dylib

config/Makefile.darwin-universal

@@ -10,7 +10,7 @@ LIBTOOL = libtool -static -o
 STRIP = 
 CFLAGS.EXTRA = -dynamic -fno-common
 CFLAGS.EXTRA += -std=c89 -pedantic
-#CFLAGS.EXTRA += -no-cpp-precomp
+CFLAGS.EXTRA += -fPIC
 CFLAGS.EXTRA += -arch i386 -arch x86_64
 LDFLAGS.EXTRA = -arch i386 -arch x86_64
 ifneq (undefined, $(origin GLEW_APPLE_GLX))
@@ -22,7 +22,6 @@ endif
 LDFLAGS.DYNAMIC =
 WARN = -Wall -W
 POPT = -Os
-CFLAGS.EXTRA += -fPIC
 BIN.SUFFIX =
 LIB.SONAME    = lib$(NAME).$(SO_MAJOR).dylib
 LIB.DEVLNK    = lib$(NAME).dylib

config/Makefile.darwin-x86_64

@@ -2,9 +2,10 @@ GLEW_DEST = /usr/local
 NAME = $(GLEW_NAME)
 CC = cc
 LD = cc
-CFLAGS.EXTRA = -arch x86_64 -dynamic -fno-common
+CFLAGS.EXTRA += -arch x86_64
+CFLAGS.EXTRA += -dynamic -fno-common
 CFLAGS.EXTRA += -std=c89 -pedantic
-#CFLAGS.EXTRA += -no-cpp-precomp
+CFLAGS.EXTRA += -fPIC
 LDFLAGS.EXTRA = -arch x86_64
 ifneq (undefined, $(origin GLEW_APPLE_GLX))
 CFLAGS.EXTRA += -I/usr/X11R6/include -D'GLEW_APPLE_GLX'
@@ -16,7 +17,6 @@ LDFLAGS.STATIC =
 LDFLAGS.DYNAMIC =
 WARN = -Wall -W
 POPT = -Os
-CFLAGS.EXTRA += -fPIC
 BIN.SUFFIX =
 LIB.SONAME    = lib$(NAME).$(SO_MAJOR).dylib
 LIB.DEVLNK    = lib$(NAME).dylib