[LibWebRTC] Include AVX2 sources on Intel hosts

https://bugs.webkit.org/show_bug.cgi?id=258708

Reviewed by Carlos Alberto Lopez Perez.

This partially reverts 265646@main.

Include AVX2 sources if host is X86 or X64.
Build AVX2 sources with build flags '-mavx2' and '-mfma'.

* Source/ThirdParty/libwebrtc/CMakeLists.txt:
* Source/cmake/DetectAVX2.cmake: Removed.
* Source/cmake/WebKitCommon.cmake:

Canonical link: https://commits.webkit.org/265754@main

Source/ThirdParty/libwebrtc/CMakeLists.txt

@@ -1780,8 +1780,8 @@ if (WTF_CPU_X86_64 OR WTF_CPU_X86)
     )
 endif()
 
-if (WTF_CPU_X86_64 AND WTF_CPU_HAS_AVX2)
-    list(APPEND webrtc_SOURCES
+if (WTF_CPU_X86_64 OR WTF_CPU_X86)
+    list(APPEND webrtc_avx_SOURCES
         Source/webrtc/common_audio/fir_filter_avx2.cc
         Source/webrtc/common_audio/resampler/sinc_resampler_avx2.cc
         Source/webrtc/modules/audio_processing/aec3/adaptive_fir_filter_avx2.cc
@@ -1791,7 +1791,8 @@ if (WTF_CPU_X86_64 AND WTF_CPU_HAS_AVX2)
         Source/webrtc/modules/audio_processing/aec3/vector_math_avx2.cc
         Source/webrtc/modules/audio_processing/agc2/rnn_vad/vector_math_avx2.cc
     )
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native -mno-avx512f")
+    set_source_files_properties(webrtc_avx_SOURCES PROPERTIES COMPILE_OPTIONS "-mavx2;-mfma")
+    list(APPEND webrtc_SOURCES webrtc_avx_SOURCES)
     add_definitions(-DWEBRTC_ENABLE_AVX2)
 endif()
 

Source/cmake/WebKitCommon.cmake

@@ -124,13 +124,6 @@ if (NOT HAS_RUN_WEBKIT_COMMON)
         set(WTF_CPU_UNKNOWN 1)
     endif ()
 
-    if (WTF_CPU_X86_64 AND NOT CMAKE_CROSSCOMPILING)
-        include(DetectAVX2)
-        if (AVX2_SUPPORT_FOUND)
-            set(WTF_CPU_HAS_AVX2 1)
-        endif ()
-    endif ()
-
     # -----------------------------------------------------------------------------
     # Determine the operating system
     # -----------------------------------------------------------------------------