Revert "Check what will happen if we build ClickHouse with Musl"

unwind in musl is too slow, so musl build is not production ready.

This reverts commit ef30f3d.

PreLoad.cmake

@@ -78,7 +78,15 @@ if (OS MATCHES "Linux"
     AND ("$ENV{CC}" MATCHES ".*clang.*" OR CMAKE_C_COMPILER MATCHES ".*clang.*"))
 
     if (ARCH MATCHES "amd64|x86_64")
-        set (CMAKE_TOOLCHAIN_FILE "cmake/linux/toolchain-x86_64-musl.cmake" CACHE INTERNAL "")
+        # NOTE: right now musl is not ready, since unwind is too slow with it
+        #
+        # FWIW the following had been tried:
+        # - update musl
+        # - compile musl with debug
+        # - compile musl with debug and -fasynchronous-unwind-tables
+        #
+        # But none of this changes anything so far.
+        set (CMAKE_TOOLCHAIN_FILE "cmake/linux/toolchain-x86_64.cmake" CACHE INTERNAL "")
     elseif (ARCH MATCHES "^(aarch64.*|AARCH64.*|arm64.*|ARM64.*)")
         set (CMAKE_TOOLCHAIN_FILE "cmake/linux/toolchain-aarch64.cmake" CACHE INTERNAL "")
     elseif (ARCH MATCHES "^(ppc64le.*|PPC64LE.*)")