Revert "[Clang] [Test] Use lit Syntax for Environment Variables in Clang subproject" (#106267)

Reverts #102647

I am reverting this change because the `readfile` doesn't actually
perform any useful operation, and yet, for some reason, the test still
passed. This indicates that the modification was unnecessary and could
lead to confusion or unexpected behavior in the future.

Author: Harini0924

clang/test/ClangScanDeps/pr61006.cppm

@@ -6,13 +6,13 @@
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 //
-// RUN: %clang -print-resource-dir > %t/resource-dir.txt && \
+// RUN: EXPECTED_RESOURCE_DIR=`%clang -print-resource-dir` && \
 // RUN: ln -s %clang++ %t/clang++ && \
-// RUN: sed "s|EXPECTED_RESOURCE_DIR|%{readfile:%t/resource-dir.txt}|g; s|DIR|%/t|g" %t/P1689.json.in > %t/P1689.json && \
-// RUN: env EXPECTED_RESOURCE_DIR=%{readfile:%t/resource-dir.txt} clang-scan-deps -compilation-database %t/P1689.json -format=p1689 | FileCheck %t/a.cpp -DPREFIX=%/t && \
-// RUN: env EXPECTED_RESOURCE_DIR=%{readfile:%t/resource-dir.txt} clang-scan-deps -format=p1689 \
+// RUN: sed "s|EXPECTED_RESOURCE_DIR|$EXPECTED_RESOURCE_DIR|g; s|DIR|%/t|g" %t/P1689.json.in > %t/P1689.json && \
+// RUN: clang-scan-deps -compilation-database %t/P1689.json -format=p1689 | FileCheck %t/a.cpp -DPREFIX=%/t && \
+// RUN: clang-scan-deps -format=p1689 \
 // RUN:   -- %t/clang++ -std=c++20 -c -fprebuilt-module-path=%t %t/a.cpp -o %t/a.o \
-// RUN:      -resource-dir %{env:EXPECTED_RESOURCE_DIR} | FileCheck %t/a.cpp -DPREFIX=%/t
+// RUN:      -resource-dir $EXPECTED_RESOURCE_DIR | FileCheck %t/a.cpp -DPREFIX=%/t
 
 //--- P1689.json.in
 [

clang/test/Driver/coverage.c

@@ -18,7 +18,7 @@
 // GCNO-LOCATION-REL: "-coverage-notes-file={{.*}}{{/|\\\\}}foo/bar.gcno"
 
 /// GCC allows PWD to change the paths.
-// RUN: %if system-linux %{ env PWD=/proc/self/cwd %clang -### -c --coverage %s -o foo/bar.o 2>&1 | FileCheck --check-prefix=PWD %s %}
+// RUN: %if system-linux %{ PWD=/proc/self/cwd %clang -### -c --coverage %s -o foo/bar.o 2>&1 | FileCheck --check-prefix=PWD %s %}
 // PWD: "-coverage-notes-file=/proc/self/cwd/foo/bar.gcno" "-coverage-data-file=/proc/self/cwd/foo/bar.gcda"
 
 /// Don't warn -Wunused-command-line-argument.
@@ -50,6 +50,6 @@
 // LINK2: -cc1{{.*}} "-coverage-notes-file={{.*}}{{/|\\\\}}f/gb.gcno" "-coverage-data-file={{.*}}{{/|\\\\}}f/gb.gcda"
 
 /// GCC allows PWD to change the paths.
-// RUN: %if system-linux %{ env PWD=/proc/self/cwd %clang -### --coverage d/a.c d/b.c -o e/x -fprofile-dir=f 2>&1 | FileCheck %s --check-prefix=LINK3 %}
+// RUN: %if system-linux %{ PWD=/proc/self/cwd %clang -### --coverage d/a.c d/b.c -o e/x -fprofile-dir=f 2>&1 | FileCheck %s --check-prefix=LINK3 %}
 // LINK3: -cc1{{.*}} "-coverage-notes-file=/proc/self/cwd/e/x-a.gcno" "-coverage-data-file=f/proc/self/cwd/e/x-a.gcda"
 // LINK3: -cc1{{.*}} "-coverage-notes-file=/proc/self/cwd/e/x-b.gcno" "-coverage-data-file=f/proc/self/cwd/e/x-b.gcda"

clang/test/Driver/program-path-priority.c

@@ -87,8 +87,8 @@
 
 /// <default-triple>-gcc has lowest priority so <triple>-gcc
 /// on PATH beats default triple in program path
-// RUN: %t/clang --version | grep "Target:" | cut -d ' ' -f2 > %t/default-triple.txt
-// RUN: env DEFAULT_TRIPLE=%{readfile:%t/default-triple.txt} touch %t/%{env:DEFAULT_TRIPLE}-gcc && chmod +x %t/%{env:DEFAULT_TRIPLE}-gcc
+// RUN: DEFAULT_TRIPLE=`%t/clang --version | grep "Target:" | cut -d ' ' -f2`
+// RUN: touch %t/$DEFAULT_TRIPLE-gcc && chmod +x %t/$DEFAULT_TRIPLE-gcc
 // RUN: touch %t/%target_triple-gcc && chmod +x %t/%target_triple-gcc
 // RUN: env "PATH=%t/env/" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=DEFAULT_TRIPLE_GCC %s