Revert "[TSan] Make Test work with Internal Shell"

This reverts commit 8761693.

This broke a buildbot. Reverting so I can ensure I'm comitting with the
proper fix given this didn't reporoduce locally on my Linux box.

https://lab.llvm.org/buildbot/#/builders/174/builds/26760

Author: boomanaiden154

compiler-rt/test/tsan/ignore_lib0.cpp

@@ -4,13 +4,11 @@
 // RUN: %clangxx_tsan -O1 -fno-builtin %s -DLIB -fPIC -fno-sanitize=thread -shared -o %t-dir/libignore_lib0.so
 // RUN: %clangxx_tsan -O1 %s -L%t-dir -lignore_lib0 %link_libcxx_tsan -o %t
 // RUN: echo running w/o suppressions:
-// RUN: echo -n %t-dir > %t.ld_library_path
-// RUN: python -c "if 'LD_LIBRARY_PATH' in __import__('os').environ: print(':' + __import__('os').environ['LD_LIBRARY_PATH'], end='')" >> %t.ld_library_path
-// RUN: env LD_LIBRARY_PATH=%{readfile:%t.ld_library_path} %deflake %run %t | FileCheck %s --check-prefix=CHECK-NOSUPP
+// RUN: env LD_LIBRARY_PATH=%t-dir${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH} %deflake %run %t | FileCheck %s --check-prefix=CHECK-NOSUPP
 // RUN: echo running with suppressions:
-// RUN: env LD_LIBRARY_PATH=%{readfile:%t.ld_library_path} %env_tsan_opts=suppressions='%s.supp' %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-WITHSUPP
+// RUN: env LD_LIBRARY_PATH=%t-dir${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH} %env_tsan_opts=suppressions='%s.supp' %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-WITHSUPP
 // RUN: echo running with generic suppression of noninstrumented code:
-// RUN: env LD_LIBRARY_PATH=%{readfile:%t.ld_library_path} %env_tsan_opts=ignore_noninstrumented_modules=1 %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-WITHSUPP
+// RUN: env LD_LIBRARY_PATH=%t-dir${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH} %env_tsan_opts=ignore_noninstrumented_modules=1 %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-WITHSUPP
 
 // Tests that interceptors coming from a library specified in called_from_lib
 // suppression are ignored.