servo: Merge #16958 - -Z wr-no-batch option (from kvark:no-batch); r=jdm

<!-- Please describe your changes on the following line: -->

This new debug option exposes servo/webrender#1186

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [x] These changes do not require tests because _____ it's a debug option

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Source-Repo: https://github.com/servo/servo
Source-Revision: b42ee29c1bc66484406c289c70aa5c4795728743

UltraBlame original commit: b81b9a65cfa09fb8b55d5ce0d16f7346ee615eba

servo/components/config/opts.rs

@@ -1423,6 +1423,25 @@ bool
 /
 /
 True
+if
+webrender
+is
+allowed
+to
+batch
+draw
+calls
+as
+instances
+.
+pub
+webrender_batch
+:
+bool
+/
+/
+/
+True
 to
 compile
 all
@@ -2078,6 +2097,20 @@ bool
 /
 /
 /
+Enable
+webrender
+instanced
+draw
+call
+batching
+.
+pub
+webrender_batch
+:
+bool
+/
+/
+/
 Use
 multisample
 antialiasing
@@ -2567,6 +2600,20 @@ webrender_record
 =
 true
 "
+wr
+-
+no
+-
+batch
+"
+=
+>
+self
+.
+webrender_batch
+=
+false
+"
 msaa
 "
 =
@@ -3225,6 +3272,24 @@ borders
 print_option
 (
 "
+wr
+-
+no
+-
+batch
+"
+"
+Disable
+webrender
+instanced
+batching
+.
+"
+)
+;
+print_option
+(
+"
 precache
 -
 shaders
@@ -4014,6 +4079,9 @@ false
 webrender_record
 :
 false
+webrender_batch
+:
+true
 precache_shaders
 :
 false
@@ -7028,6 +7096,11 @@ webrender_record
 debug_options
 .
 webrender_record
+webrender_batch
+:
+debug_options
+.
+webrender_batch
 precache_shaders
 :
 debug_options

servo/components/servo/lib.rs

@@ -1383,6 +1383,11 @@ enable_profiler
 opts
 .
 webrender_stats
+enable_batcher
+:
+opts
+.
+webrender_batch
 debug
 :
 opts