Fix for MesaLib build

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

Hello

For now MesaLib build is broken, which in turn prevents modular-xorg-server 
to build.

I got MesaLib (and modular-xorg-server) to build with the patch below.
Is it okay to commit?

--- graphics/MesaLib/Makefile   21 Jan 2020 14:41:26 -0000      1.183
+++ graphics/MesaLib/Makefile   29 Jan 2020 08:04:58 -0000
@@ -16,9 +16,9 @@
 USE_LANGUAGES= c99 c++14
 USE_LIBTOOL=   yes
 
 # ERROR: C++ Compiler does not support -std=c++14
-GCC_REQD+=     5
+GCC_REQD+=     8
 
 USE_FEATURES+= strnlen
 
 CFLAGS.SunOS+=         -D_POSIX_PTHREAD_SEMANTICS
Index: lang/libLLVM/Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/lang/libLLVM/Makefile,v
retrieving revision 1.33
diff -U4 -r1.33 Makefile
--- lang/libLLVM/Makefile       3 Nov 2019 19:04:02 -0000       1.33
+++ lang/libLLVM/Makefile       29 Jan 2020 08:04:58 -0000
@@ -13,9 +13,9 @@
 LICENSE=       modified-bsd
 
 USE_LANGUAGES=         c c++11
 USE_CMAKE=             yes
-GCC_REQD+=             4.8
+GCC_REQD+=             8
 PYTHON_FOR_BUILD_ONLY= yes
 
 CONFIGURE_DIRS=                ${WRKDIR}/build
 CMAKE_ARG_PATH=                ${WRKSRC}


-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost