os: implement waitable management.

This implements waitable management for Events (and
implements Events). It also refactors PM to use new
Event/Waitable semantics, and also adds STS_ASSERT
as a macro for asserting a boolean expression. The
rest of stratosphere has been refactored to use
STS_ASSERT whenever possible.

stratosphere/boot/source/pinmux/pinmux_initial_configuration.cpp

@@ -66,9 +66,7 @@ namespace sts::pinmux {
             }
 
             /* Ensure we found an appropriate config. */
-            if (configs == nullptr) {
-                std::abort();
-            }
+            STS_ASSERT(configs != nullptr);
 
             for (size_t i = 0; i < num_configs; i++) {
                 UpdatePad(configs[i].name, configs[i].val, configs[i].mask);

stratosphere/boot/source/pinmux/pinmux_utils.cpp

@@ -33,19 +33,13 @@ namespace sts::pinmux {
 
         /* Helpers. */
         inline const Definition *GetDefinition(u32 pinmux_name) {
-            if (pinmux_name >= PadNameMax) {
-                std::abort();
-            }
-
+            STS_ASSERT(pinmux_name < PadNameMax);
             return &Map[pinmux_name];
         }
 
-        inline const DrivePadDefinition *GetDrivePadDefinition(u32 pinmux_name) {
-            if (pinmux_name >= DrivePadNameMax) {
-                std::abort();
-            }
-
-            return &DrivePadMap[pinmux_name];
+        inline const DrivePadDefinition *GetDrivePadDefinition(u32 drivepad_name) {
+            STS_ASSERT(drivepad_name < DrivePadNameMax);
+            return &DrivePadMap[drivepad_name];
         }
 
         uintptr_t GetBaseAddress() {
@@ -110,9 +104,7 @@ namespace sts::pinmux {
         u32 pinmux_val = reg::Read(pinmux_reg);
 
         /* This PINMUX register is locked */
-        if (pinmux_val & 0x80) {
-            std::abort();
-        }
+        STS_ASSERT((pinmux_val & 0x80) == 0);
 
         u32 pm_val = (pinmux_config_val & 0x07);