[compiler-rt][NFC] Replace environment variable with %t (#102197)

Certain tests within the compiler-rt subproject encountered "command not
found" errors when using lit's internal shell, particularly when trying
to use the `DIR` environment variable. When checking with the command
`LIT_USE_INTERNAL_SHELL=1 ninja check-compiler-rt`, I encountered the
following error:
```
********************
Testing: 
FAIL: SanitizerCommon-ubsan-i386-Linux :: sanitizer_coverage_trace_pc_guard-init.cpp (146 of 9570)
******************** TEST 'SanitizerCommon-ubsan-i386-Linux :: sanitizer_coverage_trace_pc_guard-init.cpp' FAILED ********************
Exit Code: 127

Command Output (stdout):
--
# RUN: at line 5
DIR=/usr/local/google/home/harinidonthula/llvm-project/build/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/ubsan-i386-Linux/Output/sanitizer_coverage_trace_pc_guard-init.cpp.tmp_workdir
# executed command: DIR=/usr/local/google/home/harinidonthula/llvm-project/build/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/ubsan-i386-Linux/Output/sanitizer_coverage_trace_pc_guard-init.cpp.tmp_workdir
# .---command stderr------------
# | 'DIR=/usr/local/google/home/harinidonthula/llvm-project/build/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/ubsan-i386-Linux/Output/sanitizer_coverage_trace_pc_guard-init.cpp.tmp_workdir': command not found
# `-----------------------------
# error: command failed with exit status: 127
```
In this patch, I resolved these issues by removing the use of the `DIR`
environment variable. Instead, the tests now directly utilize
`%t_workdir` for managing temporary directories. Additionally, I
simplified the tests by embedding the clang command arguments directly
into the test scripts, which avoids complications with environment
variable expansion under lit's internal shell.

This fix ensures that the tests run smoothly with lit's internal shell
and prevents the "command not found" errors, improving the reliability
of the test suite when executed in this environment.

fixes: #102395
[link to
RFC](https://discourse.llvm.org/t/rfc-enabling-the-lit-internal-shell-by-default/80179)

Author: Harini0924

compiler-rt/test/sanitizer_common/TestCases/sanitizer_coverage_allowlist_ignorelist.cpp

@@ -7,10 +7,9 @@
 // XFAIL: ubsan,tsan
 // XFAIL: android && asan
 
-// RUN: DIR=%t_workdir
-// RUN: rm -rf $DIR
-// RUN: mkdir -p $DIR
-// RUN: cd $DIR
+// RUN: rm -rf %t_workdir
+// RUN: mkdir -p %t_workdir
+// RUN: cd %t_workdir
 
 // RUN: echo -e "src:*\nfun:*"     > al_all.txt
 // RUN: echo -e ""                 > al_none.txt
@@ -82,7 +81,7 @@
 // RUN: %clangxx -O0 %s -S -o - -emit-llvm -fsanitize-coverage=inline-8bit-counters,indirect-calls,trace-cmp,pc-table -fsanitize-coverage-allowlist=al_bar.txt  -fsanitize-coverage-ignorelist=bl_bar.txt   2>&1 | not grep -f patterns.txt
 
 // RUN: cd -
-// RUN: rm -rf $DIR
+// RUN: rm -rf %t_workdir
 
 // foo has 3 instrumentation points, 0 indirect call, 1 comparison point
 

compiler-rt/test/sanitizer_common/TestCases/sanitizer_coverage_symbolize.cpp

@@ -3,15 +3,14 @@
 // REQUIRES: x86_64-linux
 // XFAIL: tsan
 //
-// RUN: DIR=%t_workdir
-// RUN: rm -rf $DIR
-// RUN: mkdir -p $DIR
-// RUN: cd $DIR
+// RUN: rm -rf %t_workdir
+// RUN: mkdir -p %t_workdir
+// RUN: cd %t_workdir
 /// In glibc 2.39+, fprintf has a nonnull attribute. Disable nonnull-attribute,
 /// which would increase counters for ubsan.
 // RUN: %clangxx -O0 -fsanitize-coverage=trace-pc-guard -fno-sanitize=nonnull-attribute %s -o %t
 // RUN: %env_tool_opts=coverage=1 %t 2>&1 | FileCheck %s
-// RUN: rm -rf $DIR
+// RUN: rm -rf %t_workdir
 
 #include <stdio.h>
 

compiler-rt/test/sanitizer_common/TestCases/sanitizer_coverage_trace_pc_guard-dso.cpp

@@ -5,19 +5,17 @@
 // XFAIL: tsan,darwin
 // XFAIL: android && asan
 
-// RUN: DIR=%t_workdir
-// RUN: CLANG_ARGS="-O0 -fsanitize-coverage=trace-pc-guard"
-// RUN: rm -rf $DIR
-// RUN: mkdir -p $DIR
-// RUN: cd $DIR
-// RUN: %clangxx -DSHARED1 $CLANG_ARGS -shared %s -o %t_1.so -fPIC
-// RUN: %clangxx -DSHARED2 $CLANG_ARGS -shared %s -o %t_2.so -fPIC
-// RUN: %clangxx -DMAIN $CLANG_ARGS %s -o %t %t_1.so %t_2.so
+// RUN: rm -rf %t_workdir
+// RUN: mkdir -p %t_workdir
+// RUN: cd %t_workdir
+// RUN: %clangxx -DSHARED1 -O0 -fsanitize-coverage=trace-pc-guard -shared %s -o %t_1.so -fPIC
+// RUN: %clangxx -DSHARED2 -O0 -fsanitize-coverage=trace-pc-guard -shared %s -o %t_2.so -fPIC
+// RUN: %clangxx -DMAIN -O0 -fsanitize-coverage=trace-pc-guard %s -o %t %t_1.so %t_2.so
 // RUN: %env_tool_opts=coverage=1 %t 2>&1 | FileCheck %s
 // RUN: %sancovcc  -covered-functions -strip_path_prefix=TestCases/ *.sancov \
 // RUN:            %t %t_1.so %t_2.so 2>&1 | \
 // RUN:   FileCheck --check-prefix=CHECK-SANCOV %s
-// RUN: rm -rf $DIR
+// RUN: rm -rf %t_workdir
 
 #include <stdio.h>
 

compiler-rt/test/sanitizer_common/TestCases/sanitizer_coverage_trace_pc_guard-init.cpp

@@ -2,16 +2,14 @@
 //
 // REQUIRES: has_sancovcc,stable-runtime,x86_64-linux
 //
-// RUN: DIR=%t_workdir
-// RUN: CLANG_ARGS="-O0 -fsanitize-coverage=trace-pc-guard"
-// RUN: rm -rf $DIR
-// RUN: mkdir -p $DIR
-// RUN: cd $DIR
-// RUN: %clangxx -DSHARED1 $CLANG_ARGS -shared %s -o %t_1.so -fPIC
-// RUN: %clangxx -DSTATIC1 $CLANG_ARGS %s -c -o %t_2.o
-// RUN: %clangxx -DMAIN $CLANG_ARGS %s -o %t %t_1.so %t_2.o
+// RUN: rm -rf %t_workdir
+// RUN: mkdir -p %t_workdir
+// RUN: cd %t_workdir
+// RUN: %clangxx -DSHARED1 -O0 -fsanitize-coverage=trace-pc-guard -shared %s -o %t_1.so -fPIC
+// RUN: %clangxx -DSTATIC1 -O0 -fsanitize-coverage=trace-pc-guard %s -c -o %t_2.o
+// RUN: %clangxx -DMAIN -O0 -fsanitize-coverage=trace-pc-guard %s -o %t %t_1.so %t_2.o
 // RUN: %env_tool_opts=coverage=1 %t 2>&1 | FileCheck %s
-// RUN: rm -rf $DIR
+// RUN: rm -rf %t_workdir
 
 #include <stdio.h>
 #include <stdint.h>

compiler-rt/test/sanitizer_common/TestCases/sanitizer_coverage_trace_pc_guard.cpp

@@ -7,16 +7,15 @@
 // XFAIL: tsan
 // XFAIL: android && asan
 
-// RUN: DIR=%t_workdir
-// RUN: rm -rf $DIR
-// RUN: mkdir -p $DIR
-// RUN: cd $DIR
+// RUN: rm -rf %t_workdir
+// RUN: mkdir -p %t_workdir
+// RUN: cd %t_workdir
 // RUN: %clangxx -O0 -fsanitize-coverage=trace-pc-guard %s -o %t
 // RUN: %env_tool_opts=coverage=1 %t 2>&1 | FileCheck %s
 // RUN: %sancovcc  -covered-functions -strip_path_prefix=TestCases/ *.sancov %t 2>&1 | \
 // RUN:   FileCheck --check-prefix=CHECK-SANCOV %s
 // RUN: %env_tool_opts=coverage=0 %t 2>&1 | FileCheck --check-prefix=CHECK-NOCOV %s
-// RUN: rm -rf $DIR
+// RUN: rm -rf %t_workdir
 // Make some room to stabilize line numbers
 
 #include <stdio.h>