Revert "Add ARM64X support"

This reverts commit 64effa9a71.

It turns out that the LLD handling of the TLS data structures
("_tls_used" and "_tls_index") needs more work, causing the
arm64ec side of arm64x binaries to not get them hooked up properly.

build-openmp.sh

@@ -64,26 +64,12 @@ else
     esac
 fi
 
-ARM64X_FLAGS=""
-for arch in $ARCHS; do
-    case $arch in
-    arm64ec) ARM64X_FLAGS="-marm64x" ;;
-    esac
-done
-
 for arch in $ARCHS; do
     CMAKEFLAGS=""
-    FLAGS=""
     case $arch in
     x86_64)
         CMAKEFLAGS="$CMAKEFLAGS -DLIBOMP_ASMFLAGS=-m64"
         ;;
-    aarch64)
-        FLAGS="$ARM64X_FLAGS"
-        ;;
-    arm64ec)
-        continue
-        ;;
     esac
 
     [ -z "$CLEAN" ] || rm -rf build-openmp-$arch
@@ -104,9 +90,8 @@ for arch in $ARCHS; do
         -DCMAKE_RANLIB="$PREFIX/bin/llvm-ranlib" \
         -DLLVM_ENABLE_RUNTIMES="openmp" \
         -DLIBOMP_ENABLE_SHARED=TRUE \
-        -DCMAKE_C_FLAGS_INIT="$CFGUARD_CFLAGS $FLAGS" \
-        -DCMAKE_CXX_FLAGS_INIT="$CFGUARD_CFLAGS $FLAGS" \
-        -DCMAKE_SHARED_LINKER_FLAGS="$FLAGS" \
+        -DCMAKE_C_FLAGS_INIT="$CFGUARD_CFLAGS" \
+        -DCMAKE_CXX_FLAGS_INIT="$CFGUARD_CFLAGS" \
         $CMAKEFLAGS \
         ..
     cmake --build . ${CORES:+-j${CORES}}