patch 8.2.3356: adding many text properties requires a lot of function calls

Problem:    Adding many text properties requires a lot of function calls.
Solution:   Add the prop_add_list() function. (Yegappan Lakshmanan,
            closes #8751)

runtime/doc/eval.txt

@@ -2801,7 +2801,9 @@ prompt_getprompt({buf})		String	get prompt text
 prompt_setcallback({buf}, {expr}) none	set prompt callback function
 prompt_setinterrupt({buf}, {text}) none	set prompt interrupt function
 prompt_setprompt({buf}, {text}) none	set prompt text
-prop_add({lnum}, {col}, {props})  none	add a text property
+prop_add({lnum}, {col}, {props})  none	add one text property
+prop_add_list({props}, [[{lnum}, {col}, {end-lnum}, {end-col}], ...])
+				none	add multiple text properties
 prop_clear({lnum} [, {lnum-end} [, {props}]])
 				none	remove all text properties
 prop_find({props} [, {direction}])

runtime/doc/textprop.txt

@@ -108,6 +108,9 @@ prop_type_list([{props}])		get list of property types
 Manipulating text properties:
 
 prop_add({lnum}, {col}, {props})  	add a text property
+prop_add_list({props}, [[{lnum}, {col}, {end-lnum}, {end-col}], ...])
+					add a text property at multiple
+					positions.
 prop_clear({lnum} [, {lnum-end} [, {bufnr}]])
 					remove all text properties
 prop_find({props} [, {direction}])	search for a text property
@@ -158,6 +161,35 @@ prop_add({lnum}, {col}, {props})
 		Can also be used as a |method|: >
 			GetLnum()->prop_add(col, props)
 
+						*prop_add_list()*
+prop_add_list({props}, [[{lnum}, {col}, {end-lnum}, {end-col}], ...])
+		Similar to prop_add(), but attaches a text property at
+		multiple positions in a buffer.
+
+		{props} is a dictionary with these fields:
+		   bufnr	buffer to add the property to; when omitted
+				the current buffer is used
+		   id		user defined ID for the property; must be a
+				number; when omitted zero is used
+		   type		name of the text property type
+		All fields except "type" are optional.
+
+		The second argument is a List of Lists where each list
+		specifies the starting and ending position of the text.  The
+		first two items {lnum} and {col} specify the starting position
+		of the text where the property will be attached and the last
+		two items {end-lnum} and {end-col} specify the position just
+		after the text.
+
+		Example:
+			call prop_add_list(#{type: 'MyProp', id: 2},
+					\ [[1, 4, 1, 7],
+					\  [1, 15, 1, 20],
+					\  [2, 30, 3, 30]]
+
+		Can also be used as a |method|: >
+			GetProp()->prop_add_list([[1, 1, 1, 2], [1, 4, 1, 8]])
+
 
 prop_clear({lnum} [, {lnum-end} [, {props}]])		*prop_clear()*
 		Remove all text properties from line {lnum}.

runtime/doc/usr_41.txt

@@ -1161,6 +1161,7 @@ Prompt Buffer:					*promptbuffer-functions*
 
 Text Properties:				*text-property-functions*
 	prop_add()		attach a property at a position
+	prop_add_list()		attach a property at multiple positions
 	prop_clear()		remove all properties from a line or lines
 	prop_find()		search for a property
 	prop_list()		return a list of all properties in a line