[compiler-rt] Support building runtimes for Windows on arm32 (#101462)

In these environments, the architecture name is armv7; recognize that
and enable the relevant runtimes.

Fix building the sanitizer_common library for this target, by using the
right registers for the architecture - this is similar to what
0c39113 did for aarch64.

(Still, address sanitizer doesn't support hooking functions at runtime
on armv7 or aarch64 - but other runtimes such as ubsan do work.)

(cherry picked from commit 5ea9dd8)

Author: mstorsjo

compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake

@@ -24,6 +24,10 @@ if(APPLE)
   set(X86_64 x86_64 x86_64h)
 endif()
 
+if(WIN32)
+  set(ARM32 ${ARM32} armv7)
+endif()
+
 set(ALL_SANITIZER_COMMON_SUPPORTED_ARCH ${X86} ${X86_64} ${PPC64} ${RISCV64}
     ${ARM32} ${ARM64} ${MIPS32} ${MIPS64} ${S390X} ${SPARC} ${SPARCV9}
     ${HEXAGON} ${LOONGARCH64})

compiler-rt/lib/sanitizer_common/sanitizer_unwind_win.cpp

@@ -70,10 +70,17 @@ void BufferedStackTrace::UnwindSlow(uptr pc, void *context, u32 max_depth) {
   stack_frame.AddrStack.Offset = ctx.Rsp;
 #      endif
 #    else
+#      if SANITIZER_ARM
+  int machine_type = IMAGE_FILE_MACHINE_ARM;
+  stack_frame.AddrPC.Offset = ctx.Pc;
+  stack_frame.AddrFrame.Offset = ctx.R11;
+  stack_frame.AddrStack.Offset = ctx.Sp;
+#      else
   int machine_type = IMAGE_FILE_MACHINE_I386;
   stack_frame.AddrPC.Offset = ctx.Eip;
   stack_frame.AddrFrame.Offset = ctx.Ebp;
   stack_frame.AddrStack.Offset = ctx.Esp;
+#      endif
 #    endif
   stack_frame.AddrPC.Mode = AddrModeFlat;
   stack_frame.AddrFrame.Mode = AddrModeFlat;

compiler-rt/lib/sanitizer_common/sanitizer_win.cpp

@@ -992,8 +992,13 @@ void SignalContext::InitPcSpBp() {
   sp = (uptr)context_record->Rsp;
 #    endif
 #  else
+#    if SANITIZER_ARM
+  bp = (uptr)context_record->R11;
+  sp = (uptr)context_record->Sp;
+#    else
   bp = (uptr)context_record->Ebp;
   sp = (uptr)context_record->Esp;
+#    endif
 #  endif
 }