i965/hiz: Convert gen{6,7}_hiz.c to C++

This patch converts the files gen6_hiz.c and gen7_hiz.c to C++, in
preparation for expanding the HiZ code to support arbitrary blits.

The new files are called gen6_blorp.cpp and gen7_blorp.cpp to reflect
the expanded role that this code will serve--"blorp" stands for "BLit
Or Resolve Pass".

Reviewed-by: Chad Versace <chad.versace@linux.intel.com>

src/mesa/drivers/dri/i965/Makefile.sources

@@ -88,7 +88,6 @@ i965_C_FILES = \
 	gen6_clip_state.c \
 	gen6_depthstencil.c \
 	gen6_gs_state.c \
-	gen6_hiz.c \
 	gen6_sampler_state.c \
 	gen6_scissor_state.c \
 	gen6_sf_state.c \
@@ -100,7 +99,6 @@ i965_C_FILES = \
 	gen7_cc_state.c \
 	gen7_clip_state.c \
 	gen7_disable.c \
-	gen7_hiz.c \
 	gen7_misc_state.c \
 	gen7_sampler_state.c \
 	gen7_sf_state.c \
@@ -127,6 +125,8 @@ i965_CXX_FILES = \
 	brw_vec4_emit.cpp \
 	brw_vec4_copy_propagation.cpp \
 	brw_vec4_reg_allocate.cpp \
-	brw_vec4_visitor.cpp
+	brw_vec4_visitor.cpp \
+	gen6_blorp.cpp \
+	gen7_blorp.cpp
 
 i965_ASM_FILES =