[clang] [PS4,PS5][Driver] Check for absent SDK when -nostdlib/-nodefaultlibs (PR #107112)

[Jeremy Morse via cfe-commits]

================
@@ -36,9 +35,6 @@
 // RUN: env SCE_ORBIS_SDK_DIR=.. %clang -Winvalid-or-nonexistent-directory -### -emit-ast -isysroot foo -target x86_64-scei-ps4 %s 2>&1 | FileCheck -check-prefix=WARN-ISYSROOT -check-prefix=NO-WARN %s
 // RUN: env SCE_ORBIS_SDK_DIR=.. %clang -Winvalid-or-nonexistent-directory -### --sysroot=foo/ -isysroot foo -target x86_64-scei-ps4 %s 2>&1 | FileCheck -check-prefix=WARN-ISYSROOT -check-prefix=NO-WARN %s
 
-// RUN: env SCE_ORBIS_SDK_DIR=.. %clang -Winvalid-or-nonexistent-directory -### -nostdlib -target x86_64-scei-ps4 %s 2>&1 | FileCheck -check-prefix=WARN-SYS-HEADERS -check-prefix=NO-WARN %s
-// RUN: env SCE_ORBIS_SDK_DIR=.. %clang -Winvalid-or-nonexistent-directory -### -nodefaultlibs -target x86_64-scei-ps4 %s 2>&1 | FileCheck -check-prefix=WARN-SYS-HEADERS -check-prefix=NO-WARN %s
----------------
jmorse wrote:

Just to confirm my understanding, we're intending that the library check occurs, testing that the diagnostic occurs should be covered by an earlier RUN line, thus it's correct to delete these?

The opposing view would be "we're changing the compiler-driver behaviour, so should positively test that it does what we want", which would mean leaving these RUN lines here and checking that they behave the same as without the flags (i.e. `--check-prefixes=WARN-SYS-HEADERS,WARN-SYS-LIBS,NO-WARN`). I lean slightly in this direction, @pogo59 how do you feel?

https://github.com/llvm/llvm-project/pull/107112