Makefile: support passing in arguments to check_spelling.py

Handy to support different checks.

GNUmakefile

@@ -99,6 +99,9 @@ Spell Checkers
    Example:
       make check_spelling_c CHECK_SPELLING_CACHE=../spelling_cache.data
 
+   Note: additonal arguments can be passed in via: 'CHECK_SPELLING_EXTRA_ARGS'.
+   See the output of './tools/check_source/check_spelling.py --help' for details.
+
 Utilities
    Not associated with building Blender.
 
@@ -524,6 +527,7 @@ check_spelling_py: .FORCE
 	    "$(BLENDER_DIR)/tools/check_source/check_spelling.py" \
 	    --cache-file=$(CHECK_SPELLING_CACHE) \
 	    --match=".*\.(py)$$" \
+	    $(CHECK_SPELLING_EXTRA_ARGS) \
 	    "$(BLENDER_DIR)/release" \
 	    "$(BLENDER_DIR)/scripts" \
 	    "$(BLENDER_DIR)/source" \
@@ -536,6 +540,7 @@ check_spelling_c: .FORCE
 	    "$(BLENDER_DIR)/tools/check_source/check_spelling.py" \
 	    --cache-file=$(CHECK_SPELLING_CACHE) \
 	    --match=".*\.(c|cc|cpp|cxx|h|hh|hpp|hxx|inl|m|mm)$$" \
+	    $(CHECK_SPELLING_EXTRA_ARGS) \
 	    "$(BLENDER_DIR)/source" \
 	    "$(BLENDER_DIR)/intern/cycles" \
 	    "$(BLENDER_DIR)/intern/guardedalloc" \
@@ -546,6 +551,7 @@ check_spelling_shaders: .FORCE
 	    "$(BLENDER_DIR)/tools/check_source/check_spelling.py" \
 	    --cache-file=$(CHECK_SPELLING_CACHE) \
 	    --match=".*\.(osl|metal|msl|glsl)$$" \
+	    $(CHECK_SPELLING_EXTRA_ARGS) \
 	    "$(BLENDER_DIR)/intern/" \
 	    "$(BLENDER_DIR)/source/"
 
@@ -555,6 +561,7 @@ check_spelling_cmake: .FORCE
 	    --cache-file=$(CHECK_SPELLING_CACHE) \
 	    --match=".*\.(cmake)$$" \
 	    --match=".*\bCMakeLists\.(txt)$$" \
+	    $(CHECK_SPELLING_EXTRA_ARGS) \
 	    "$(BLENDER_DIR)/build_files/" \
 	    "$(BLENDER_DIR)/intern/" \
 	    "$(BLENDER_DIR)/source/"