Cleanup: use STREQUAL instead of MATCHES for exact comparisons

MATCHES takes a REGEX and searches the input for a match,
this isn't necessary for CMAKE_SYSTEM_PROCESSOR & CMAKE_*_COMPILER_ID.

intern/cycles/CMakeLists.txt

@@ -77,7 +77,7 @@ elseif(NOT WITH_CPU_SIMD OR (SUPPORT_NEON_BUILD AND SSE2NEON_FOUND))
   set(CXX_HAS_SSE42 FALSE)
   set(CXX_HAS_AVX FALSE)
   set(CXX_HAS_AVX2 FALSE)
-elseif(WIN32 AND MSVC AND NOT CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+elseif(WIN32 AND MSVC AND NOT CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
   set(CXX_HAS_SSE42 TRUE)
   set(CXX_HAS_AVX TRUE)
   set(CXX_HAS_AVX2 TRUE)
@@ -116,7 +116,7 @@ elseif(WIN32 AND MSVC AND NOT CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   string(APPEND CMAKE_CXX_FLAGS_RELEASE " /Ox")
   string(APPEND CMAKE_CXX_FLAGS_RELWITHDEBINFO " /Ox")
   string(APPEND CMAKE_CXX_FLAGS_MINSIZEREL " /Ox")
-elseif(CMAKE_COMPILER_IS_GNUCC OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang"))
+elseif(CMAKE_COMPILER_IS_GNUCC OR (CMAKE_CXX_COMPILER_ID STREQUAL "Clang"))
   check_cxx_compiler_flag(-msse4.2 CXX_HAS_SSE42)
   check_cxx_compiler_flag(-mavx CXX_HAS_AVX)
   check_cxx_compiler_flag(-mavx2 CXX_HAS_AVX2)
@@ -150,7 +150,7 @@ elseif(CMAKE_COMPILER_IS_GNUCC OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang"))
     string(APPEND CMAKE_CXX_FLAGS " ${CYCLES_KERNEL_FLAGS}")
   endif()
 
-elseif(WIN32 AND CMAKE_CXX_COMPILER_ID MATCHES "Intel")
+elseif(WIN32 AND CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
   check_cxx_compiler_flag(/QxSSE4.2 CXX_HAS_SSE42)
   check_cxx_compiler_flag(/arch:AVX CXX_HAS_AVX)
   check_cxx_compiler_flag(/QxCORE-AVX2 CXX_HAS_AVX2)
@@ -162,7 +162,7 @@ elseif(WIN32 AND CMAKE_CXX_COMPILER_ID MATCHES "Intel")
       set(CYCLES_AVX2_KERNEL_FLAGS "/QxCORE-AVX2")
     endif()
   endif()
-elseif(CMAKE_CXX_COMPILER_ID MATCHES "Intel")
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
   check_cxx_compiler_flag(-xsse4.2 CXX_HAS_SSE42)
   check_cxx_compiler_flag(-xavx CXX_HAS_AVX)
   check_cxx_compiler_flag(-xcore-avx2 CXX_HAS_AVX2)
@@ -398,7 +398,7 @@ else()
 endif()
 
 # Warnings
-if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_C_COMPILER_ID MATCHES "Clang")
+if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
   add_check_cxx_compiler_flags(
     CMAKE_CXX_FLAGS
     _has_no_error_unused_macros "-Wno-error=unused-macros"

intern/cycles/kernel/CMakeLists.txt

@@ -1152,7 +1152,7 @@ if(WITH_COMPILER_ASAN)
     # GCC hangs compiling the big kernel files with asan and release, so disable by default.
     string(APPEND CMAKE_CXX_FLAGS_RELWITHDEBINFO " -fno-sanitize=all")
     string(APPEND CMAKE_CXX_FLAGS_DEBUG " -fno-sanitize=vptr")
-  elseif(CMAKE_C_COMPILER_ID MATCHES "Clang")
+  elseif(CMAKE_C_COMPILER_ID STREQUAL "Clang")
     # With OSL, Cycles disables rtti in some modules, which then breaks at linking
     # when trying to use vptr sanitizer (included into 'undefined' general option).
     string(APPEND CMAKE_CXX_FLAGS_RELWITHDEBINFO " -fno-sanitize=vptr")
@@ -1171,7 +1171,7 @@ if(CXX_HAS_AVX2)
 endif()
 
 # Warnings to avoid using doubles in the kernel.
-if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_C_COMPILER_ID MATCHES "Clang")
+if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
   add_check_cxx_compiler_flags(
     CMAKE_CXX_FLAGS
     _has_cxxflag_float_conversion "-Werror=float-conversion"

intern/ghost/CMakeLists.txt

@@ -382,7 +382,7 @@ elseif(WITH_GHOST_X11 OR WITH_GHOST_WAYLAND)
         DEPENDS ${INC_DST}/${_name}-client-protocol.h
       )
 
-      if(CMAKE_C_COMPILER_ID MATCHES "Clang")
+      if(CMAKE_C_COMPILER_ID STREQUAL "Clang")
         # Prevent warnings/failure to compile with generated `WL_PRIVATE` declarations.
         set_source_files_properties(
           "${INC_DST}/${_name}-client-protocol.c"