build: set CMAKE_C_STANDARD to 99 for all dependencies

Older gcc versions (4.x) require passing --std=c99 compiler flag to
prevent warnings from being emitted. Instead of setting it for each
dependency, it's easier to just pass the CMAKE_C_STANDARD flag to all
dependencies. This also prevents the scenario of us forgetting to set it
if we add new dependencies.

cmake.deps/CMakeLists.txt

@@ -14,6 +14,7 @@ include(Util)
 
 set(DEPS_CMAKE_ARGS
   -D CMAKE_C_COMPILER=${CMAKE_C_COMPILER}
+  -D CMAKE_C_STANDARD=99
   -D CMAKE_GENERATOR=${CMAKE_GENERATOR}
   -D CMAKE_GENERATOR_PLATFORM=${CMAKE_GENERATOR_PLATFORM}
   -D CMAKE_POSITION_INDEPENDENT_CODE=ON)

cmake.deps/cmake/LibvtermCMakeLists.txt

@@ -5,8 +5,6 @@ include(GNUInstallDirs)
 
 if(MSVC)
   add_definitions(-D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE)
-else()
-  add_compile_options(-std=c99)
 endif()
 
 include_directories(${CMAKE_SOURCE_DIR}/include)

cmake.deps/cmake/TreesitterCMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.10)
 project(tree-sitter C)
-set(CMAKE_C_STANDARD 99)
+
 add_library(tree-sitter lib/src/lib.c)
 target_include_directories(tree-sitter
   PRIVATE lib/src lib/include)

cmake.deps/cmake/TreesitterParserCMakeLists.txt

@@ -1,7 +1,6 @@
 cmake_minimum_required(VERSION 3.10)
 project(parser C)
 
-set(CMAKE_C_STANDARD 99)
 file(GLOB source_files src/*.c)
 
 add_library(parser

cmake.deps/cmake/libtermkeyCMakeLists.txt

@@ -3,9 +3,6 @@ project(libtermkey C)
 
 add_definitions(-D _CRT_SECURE_NO_WARNINGS)
 add_definitions(-DHAVE_UNIBILIUM)
-if(NOT MSVC)
-  add_compile_options(-std=c99)
-endif()
 
 include_directories(${PROJECT_BINARY_DIR}/t)
 include_directories(SYSTEM ${UNIBILIUM_INCLUDE_DIRS})