Simplify glslang grammar for identifier lists #1105

Job	Run time
iOS	1m 30s
android (ON)	1m 24s
emscripten	2m 14s
linux (clang, clang++, Debug)	1m 55s
android (OFF)	1m 9s
Linux Backcompat	2m 52s
linux (clang, clang++, Release)	1m 45s
linux-shared (clang, clang++, Release)	1m 35s
linux (gcc, g++, Debug)	7m 7s
linux-asan (gcc, g++, Debug, -fsanitize=address)	3m 52s
linux-shared (gcc, g++, Release)	2m 1s
linux-asan (gcc, g++, Debug, -fsanitize=thread)	8m 17s
linux (gcc, g++, Release)	1m 31s
macos (macos-14, clang, clang++, Debug)	4m 7s
linux-asan (gcc, g++, Debug, -fsanitize=undefined)	3m 41s
macos (macos-14, clang, clang++, Release)	4m 35s
macos-shared (macos-14, clang, clang++, Release)	3m 42s
macos (macos-14, gcc, g++, Debug)	5m 4s
windows (windows-2019, windows, Debug)	5m 12s
macos (macos-14, gcc, g++, Release)	4m 21s
windows-shared (windows-2019, windows, Debug)	4m 0s
windows (windows-2019, windows, Release)	5m 2s
macos (macos-13, clang, clang++, Debug)	11m 39s
windows-shared (windows-2019, windows, Release)	4m 52s
macos (macos-13, clang, clang++, Release)	10m 43s
macos (macos-13, gcc, g++, Debug)	9m 4s
macos (macos-13, gcc, g++, Release)	12m 43s
	2h 5m 57s

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