Rollup merge of #83204 - jethrogb:jb/sgx-c-build, r=joshtriplett,raoulstrackx

Simplify C compilation for Fortanix-SGX target

cc ``@raoulstrackx``

Author: Dylan-DPC

Diff for: src/ci/docker/host-x86_64/dist-various-2/Dockerfile

@@ -45,10 +45,10 @@ ENV \
     CC_armv7_unknown_linux_gnueabi=arm-linux-gnueabi-gcc-8 \
     CXX_armv7_unknown_linux_gnueabi=arm-linux-gnueabi-g++-8 \
     AR_x86_64_fortanix_unknown_sgx=ar \
-    CC_x86_64_fortanix_unknown_sgx=x86_64-fortanix-unknown-sgx-clang-11 \
-    CFLAGS_x86_64_fortanix_unknown_sgx="-mlvi-hardening -mllvm -x86-experimental-lvi-inline-asm-hardening" \
-    CXX_x86_64_fortanix_unknown_sgx=x86_64-fortanix-unknown-sgx-clang++-11 \
-    CXXFLAGS_x86_64_fortanix_unknown_sgx="-mlvi-hardening -mllvm -x86-experimental-lvi-inline-asm-hardening" \
+    CC_x86_64_fortanix_unknown_sgx=clang-11 \
+    CFLAGS_x86_64_fortanix_unknown_sgx="-D__ELF__ -isystem/usr/include/x86_64-linux-gnu -mlvi-hardening -mllvm -x86-experimental-lvi-inline-asm-hardening" \
+    CXX_x86_64_fortanix_unknown_sgx=clang++-11 \
+    CXXFLAGS_x86_64_fortanix_unknown_sgx="-D__ELF__ -isystem/usr/include/x86_64-linux-gnu -mlvi-hardening -mllvm -x86-experimental-lvi-inline-asm-hardening" \
     AR_i686_unknown_freebsd=i686-unknown-freebsd11-ar \
     CC_i686_unknown_freebsd=i686-unknown-freebsd11-clang \
     CXX_i686_unknown_freebsd=i686-unknown-freebsd11-clang++ \
@@ -71,8 +71,6 @@ COPY host-x86_64/dist-various-2/build-solaris-toolchain.sh /tmp/
 RUN /tmp/build-solaris-toolchain.sh x86_64  amd64   solaris-i386
 RUN /tmp/build-solaris-toolchain.sh sparcv9 sparcv9 solaris-sparc
 COPY host-x86_64/dist-various-2/build-x86_64-fortanix-unknown-sgx-toolchain.sh /tmp/
-COPY host-x86_64/dist-various-2/x86_64-fortanix-unknown-sgx-clang-wrap.sh /usr/bin/x86_64-fortanix-unknown-sgx-clang-11
-RUN ln -s /usr/bin/x86_64-fortanix-unknown-sgx-clang-11 /usr/bin/x86_64-fortanix-unknown-sgx-clang++-11
 RUN /tmp/build-x86_64-fortanix-unknown-sgx-toolchain.sh
 
 COPY host-x86_64/dist-various-2/build-wasi-toolchain.sh /tmp/