[gn build] Port 24117f7

Author: llvmgnsyncbot

llvm/utils/gn/secondary/clang-tools-extra/clang-doc/BUILD.gn

@@ -22,7 +22,6 @@ static_library("clang-doc") {
     "ClangDoc.cpp",
     "Generators.cpp",
     "HTMLGenerator.cpp",
-    "HTMLMustacheGenerator.cpp",
     "JSONGenerator.cpp",
     "MDGenerator.cpp",
     "Mapper.cpp",

llvm/utils/gn/secondary/clang-tools-extra/unittests/clang-doc/BUILD.gn

@@ -40,7 +40,6 @@ unittest("ClangDocTests") {
     "ClangDocTest.cpp",
     "GeneratorTest.cpp",
     "HTMLGeneratorTest.cpp",
-    "HTMLMustacheGeneratorTest.cpp",
     "JSONGeneratorTest.cpp",
     "MDGeneratorTest.cpp",
     "MergeTest.cpp",