Fix clang build.

Some math functions require c11 standard.

Author: devnexen

src/Makefile

@@ -20,7 +20,11 @@ DEPENDENCY_TARGETS=hiredis linenoise lua
 NODEPS:=clean distclean
 
 # Default settings
-STD=-std=c99 -pedantic -DREDIS_STATIC=''
+ifneq ($(CC),clang)
+  STD=-std=c99 -pedantic -DREDIS_STATIC=''
+else
+  STD=-std=c11 -pedantic -DREDIS_STATIC=''
+endif
 WARN=-Wall -W -Wno-missing-field-initializers
 OPT=$(OPTIMIZATION)