[Test] Update section_asm to work on non-ELF platforms again.

On ELF platforms, the output will be slightly different to non-ELF
platforms.  The test should ideally run everywhere, however, so
we need to be able to distinguish these platforms by changing
the lit.cfg to add some extra variables.

rdar://123504095

Author: al45tair

test/IRGen/section_asm.swift

@@ -1,27 +1,52 @@
-// RUN: %target-swift-frontend -enable-experimental-feature SymbolLinkageMarkers -primary-file %S/section.swift -S -parse-as-library | %FileCheck %s
+// RUN: %target-swift-frontend -enable-experimental-feature SymbolLinkageMarkers -primary-file %S/section.swift -S -parse-as-library | %FileCheck --check-prefix CHECK%target-os-binfmt-elf %s
+
 // REQUIRES: swift_in_compiler
 // UNSUPPORTED: CPU=wasm32
 
-// CHECK: .section{{.*}}"__TEXT,__mysection","ax"
+// CHECK: .section{{.*}}__TEXT,__mysection
 // CHECK-NOT: .section
 // CHECK: $s7section3fooyyF:
 
-// CHECK: .section{{.*}}"__TEXT,__mysection","ax"
+// CHECK: .section{{.*}}__TEXT,__mysection
 // CHECK-NOT: .section
 // CHECK: $s7section8MyStructV3fooyyF:
 
-// CHECK: .section{{.*}}"__DATA,__mysection","aw"
+// CHECK: .section{{.*}}__DATA,__mysection
 // CHECK-NOT: .section
 // CHECK: $s7section2g0Sivp:
 // CHECK-NOT: .section
 // CHECK: $s7section2g1Si_Sitvp:
 // CHECK-NOT: .section
 // CHECK: $s7section2g2Sbvp:
-// CHECK: .section{{.*}}"__DATA,__mysection","awR"
+// CHECK-NOT: .section
 // CHECK: $s7section2g3Sbvp:
-// CHECK: .section{{.*}}"__DATA,__mysection","aw"
+// CHECK-NOT: .section
 // CHECK: $s7section2g4SpySiGSgvp:
 // CHECK-NOT: .section
 // CHECK: $s7section2g5SpySiGSgvp:
 // CHECK-NOT: .section
 // CHECK: $s7section8MyStructV7static0SivpZ:
+
+// CHECKELF: .section{{.*}}"__TEXT,__mysection","ax"
+// CHECKELF-NOT: .section
+// CHECKELF: $s7section3fooyyF:
+
+// CHECKELF: .section{{.*}}"__TEXT,__mysection","ax"
+// CHECKELF-NOT: .section
+// CHECKELF: $s7section8MyStructV3fooyyF:
+
+// CHECKELF: .section{{.*}}"__DATA,__mysection","aw"
+// CHECKELF-NOT: .section
+// CHECKELF: $s7section2g0Sivp:
+// CHECKELF-NOT: .section
+// CHECKELF: $s7section2g1Si_Sitvp:
+// CHECKELF-NOT: .section
+// CHECKELF: $s7section2g2Sbvp:
+// CHECKELF: .section{{.*}}"__DATA,__mysection","awR"
+// CHECKELF: $s7section2g3Sbvp:
+// CHECKELF: .section{{.*}}"__DATA,__mysection","aw"
+// CHECKELF: $s7section2g4SpySiGSgvp:
+// CHECKELF-NOT: .section
+// CHECKELF: $s7section2g5SpySiGSgvp:
+// CHECKELF-NOT: .section
+// CHECKELF: $s7section8MyStructV7static0SivpZ:

test/lit.cfg

@@ -1027,6 +1027,46 @@ if run_os in (
              ):
   target_mandates_stable_abi = "TRUE"
   config.available_features.add('swift_only_stable_abi')
+
+if run_os in ('macosx', 'ios', 'maccatalyst', 'tvos', 'watchos', 'xros'):
+    target_os_family = 'DARWIN'
+    target_os_binfmt = 'MACH-O'
+elif run_os in ('windows-cygnus', 'windows-gnu', 'windows-msvc'):
+    target_os_family = 'WINDOWS'
+    target_os_binfmt = 'PE-COFF'
+elif run_os in ('linux-gnu', 'linux-gnueabihf', 'linux-android', 'linux-androideabi'):
+    target_os_family = 'LINUX'
+    target_os_binfmt = 'ELF'
+elif run_os in ('freebsd', 'openbsd'):
+    target_os_family = 'BSD'
+    target_os_binfmt = 'ELF'
+else:
+    target_os_family = 'UNKNOWN'
+    target_os_binfmt = 'UNKNOWN'
+
+config.available_features.add('OS_FAMILY={}'.format(target_os_family.lower()))
+config.available_features.add('OS_BINFMT={}'.format(target_os_binfmt.lower()))
+
+for family in ('DARWIN', 'WINDOWS', 'LINUX', 'BSD', 'UNKNOWN'):
+    if family == target_os_family:
+        subst = family
+    else:
+        subst = ""
+    config.substitutions.append(
+        ('%target-os-family-{}'.format(family.lower()), subst)
+    )
+config.substitutions.append(('%target-os-family', target_os_family))
+
+for binfmt in ('MACH-O', 'PE-COFF', 'ELF', 'UNKNOWN'):
+    if binfmt == target_os_binfmt:
+        subst = binfmt
+    else:
+        subst = ""
+    config.substitutions.append(
+        ('%target-os-binfmt-{}'.format(binfmt.lower()), subst)
+    )
+config.substitutions.append(('%target-os-binfmt', target_os_binfmt))
+
 config.substitutions.append(('%target-os-abi', target_os_abi))
 config.substitutions.append(('%target-os-is-maccatalyst', target_os_is_maccatalyst))
 config.substitutions.append(('%target-mandates-stable-abi',