[test-release.sh] Respect the given width in LIT runs by adding `-j` in LLVM_LIT_ARGS.

[amyk]

Summary

This patch adds allows the LIT runs within test-release.sh to obey the width that
is passed into the script. This is accomplished by adding the width in the LLVM_LIT_ARGS
CMake configuration.

[tstellar]

This looks good to me.

llvm/utils/release/test-release.sh

function configure_llvmCore() {
     cd $ObjDir
     echo "# Configuring llvm $Release-$RC $Flavor"
 
     echo "#" env CC="$c_compiler" CXX="$cxx_compiler" \
         cmake -G "$generator" \
         -DCMAKE_BUILD_TYPE=$BuildType -DLLVM_ENABLE_ASSERTIONS=$Assertions \
         -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
         -DLLVM_ENABLE_PROJECTS="$project_list" \
+        -DLLVM_LIT_ARGS="-j $NumJobs" \
         $ExtraConfigureFlags $BuildDir/llvm-project/llvm \
         2>&1 | tee $LogDir/llvm.configure-Phase$Phase-$Flavor.log
     env CC="$c_compiler" CXX="$cxx_compiler" \
         cmake -G "$generator" \
         -DCMAKE_BUILD_TYPE=$BuildType -DLLVM_ENABLE_ASSERTIONS=$Assertions \
         -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
         -DLLVM_ENABLE_PROJECTS="$project_list" \
+        -DLLVM_LIT_ARGS="-j $NumJobs" \
         $ExtraConfigureFlags $BuildDir/llvm-project/llvm \
         2>&1 | tee $LogDir/llvm.configure-Phase$Phase-$Flavor.log
 
     cd $BuildDir
 }
 
 function build_llvmCore() {
     Phase="$1"