graphics/mesa-dri Makefile.common llvm50 suggestion

[Sid]

Here is a suggestion for Makefile.common of graphics/mesa-dri so it can readily compile with llvm50, as well as llvm40. Thank you.




--- Makefile.common	        2017-11-01 17:58:49.942976000 -0500
+++ Makefile.common.llvm50	2017-11-02 01:00:06.710847000 -0500
@@ -76,8 +76,14 @@
 
 # need LLVM for libEGL wherever possible, but mixing GCC and LLVM breaks Gallium
 .if ${CHOSEN_COMPILER_TYPE} == clang \
+ || ${CHOSEN_COMPILER_VERSION} == 40 \
  || (${COMPONENT} == libs && ${ARCH} != sparc64)	# no working LLVM
-MESA_LLVM_VER?=	40
+.endif
+
+.if ${CHOSEN_COMPILER_TYPE} == clang \
+ || ${CHOSEN_COMPILER_VERSION} == 50 \
+ || (${COMPONENT} == libs && ${ARCH} != sparc64)
+MESA_LLVM_VER?=	50
 .endif
 
 .if "${MESA_LLVM_VER}" != ""