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

Reverts llvm/llvm-project#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.

patch.cherry: true
patch.metadata.original_sha: 815bf0f
patch.platforms: chromiumos
patch.version_range.from: 547155
patch.version_range.until: 547783

Change-Id: I45472c86dc99279ec1827115bd9711bd513180c6

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