Conda build scripts should build wheels in the same setup invocation as install

Using

```
python setup.py cmd1 opts1 cmd2 opts ...
```

Author: oleksandr-pavlyk

conda-recipe/bld.bat

@@ -4,13 +4,16 @@ set "LIB=%BUILD_PREFIX%\Library\lib;%BUILD_PREFIX%\compiler\lib;%LIB%"
 set "INCLUDE=%BUILD_PREFIX%\include;%INCLUDE%"
 
 "%PYTHON%" setup.py clean --all
-"%PYTHON%" setup.py install --sycl-compiler-prefix=%BUILD_PREFIX%\Library
-if errorlevel 1 exit 1
+set "INSTALL_CMD=install --sycl-compiler-prefix=%BUILD_PREFIX%\Library"
 
-rem Build wheel package
 if NOT "%WHEELS_OUTPUT_FOLDER%"=="" (
-    %PYTHON% setup.py bdist_wheel
+    rem Install and assemble wheel package from the build bits
+    "%PYTHON%" setup.py "%INSTALL_CMD%" bdist_wheel
     if errorlevel 1 exit 1
-    copy dist\dpctl*.whl %WHEELS_OUTPUT_FOLDER%
+    copy dist\dpctl*.whl "%WHEELS_OUTPUT_FOLDER%"
+    if errorlevel 1 exit 1
+) ELSE (
+    rem Only install
+    "%PYTHON%" setup.py "%INSTALL_CMD%"
     if errorlevel 1 exit 1
 )

conda-recipe/build.sh

@@ -1,23 +1,18 @@
 #!/bin/bash
 
 ${PYTHON} setup.py clean --all
-${PYTHON} setup.py install --sycl-compiler-prefix=$CONDA_PREFIX
+INSTALL_CMD="install --sycl-compiler-prefix=$CONDA_PREFIX"
 
-# Build wheel package
-if [ "$CONDA_PY" == "36" ]; then
-    WHEELS_BUILD_ARGS="-p manylinux1_x86_64"
-else
-    WHEELS_BUILD_ARGS="-p manylinux2014_x86_64"
-fi
 if [ -n "${WHEELS_OUTPUT_FOLDER}" ]; then
-    # We need dpcpp to compile dpctl_sycl_interface
-    if [ ! -z "${ONEAPI_ROOT}" ]; then
-        # Suppress error b/c it could fail on Ubuntu 18.04
-        source ${ONEAPI_ROOT}/compiler/latest/env/vars.sh || true
+    # Install packages and assemble wheel package from built bits
+    if [ "$CONDA_PY" == "36" ]; then
+        WHEELS_BUILD_ARGS="-p manylinux1_x86_64"
     else
-        echo "DPCPP is needed to build DPCTL. Abort!"
-        exit 1
+        WHEELS_BUILD_ARGS="-p manylinux2014_x86_64"
     fi
-    $PYTHON setup.py bdist_wheel ${WHEELS_BUILD_ARGS}
+    ${PYTHON} setup.py ${INSTALL_CMD} bdist_wheel ${WHEELS_BUILD_ARGS}
     cp dist/dpctl*.whl ${WHEELS_OUTPUT_FOLDER}
+else
+    # Perform regular install
+    ${PYTHON} setup.py ${INSTALL_CMD}
 fi